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• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

For ascending cholangitis in a patient with non-life threatening penicillin hypersensitivity:

Code for ceftriaxone is: 3asc

This code is valid for THREE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 72 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• If patient appears septic, treat as per severe sepsis protocol (see homepage)
• Ascending cholangitis is usually caused by enteric gram negative bacilli such as Eschericia.coli, Klebsiella spp and Enterobacter spp. Gram positive bacteria such as Enterococcus may also be implicated. Infrequently it is caused by anaerobic bacteria
• Consider an early switch to oral within 48 hours as with all abdominal infections
• Total antibiotic therapy for patients who have not undergone biliary drainage, is 7-10 days (IV and PO). For patients who have undergone biliary drainage, total antibiotic therapy is 5 days (IV and PO) after drainage

References:

See section on ascending cholangitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For ascending cholangitis in a patient with life threatening penicillin hypersensitivity intolerant of gentamicin:

Please contact infectious diseases for advice

• If patient appears septic, treat as per severe sepsis protocol (see homepage)
• Ascending cholangitis is usually caused by enteric gram negative bacilli such as Eschericia.coli, Klebsiella spp and Enterobacter spp. Gram positive bacteria such as Enterococcus may also be implicated. Infrequently it is caused by anaerobic bacteria
• Consider an early switch to oral within 48 hours as with all abdominal infections
• Total antibiotic therapy for patients who have not undergone biliary drainage, is 7-10 days (IV and PO). For patients who have undergone biliary drainage, total antibiotic therapy is 5 days (IV and PO) after drainage

References:

See section on ascending cholangitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For ascending cholangitis in a patient with life threatening penicillin hypersensitivity use:

Code for gentamicin is: 2asc

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• If patient appears septic, treat as per severe sepsis protocol (see homepage)
• Ascending cholangitis is usually caused by enteric gram negative bacilli such as Eschericia.coli, Klebsiella spp and Enterobacter spp. Gram positive bacteria such as Enterococcus may also be implicated. Infrequently it is caused by anaerobic bacteria
• Consider an early switch to oral within 48 hours as with all abdominal infections
• Total antibiotic therapy for patients who have not undergone biliary drainage, is 7-10 days (IV and PO). For patients who have undergone biliary drainage, total antibiotic therapy is 5 days (IV and PO) after drainage
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Paediatric Gentamicin Dosing (Age < 12 years)

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• For dosing in children with cystic fibrosis or those receiving chemotherapy, seek expert advice
• For children with impaired renal function (estimated glomerular filtration rate [eGFR] less than 50 mL/min/1.73 m²), give a single dose, then seek expert advice for subsequent dosing or selection of alternative drug. Use the modified Schwartz formula to estimate GFR
• Postmenstrual age is the time elapsed between the first day of the last menstrual period and birth (gestational age) plus the time elapsed after birth (postnatal age)
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on ascending cholangitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For ascending cholangitis in a patient who can tolerate penicillin and gentamicin:

Code for gentamicin is: 2asc

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• If patient appears septic, treat as per severe sepsis protocol (see homepage)
• Ascending cholangitis is usually caused by enteric gram negative bacilli such as Eschericia.coli, Klebsiella spp and Enterobacter spp. Gram positive bacteria such as Enterococcus may also be implicated. Infrequently it is caused by anaerobic bacteria
• Consider an early switch to oral within 48 hours as with all abdominal infections
• Total antibiotic therapy for patients who have not undergone biliary drainage, is 7-10 days (IV and PO). For patients who have undergone biliary drainage, total antibiotic therapy is 5 days (IV and PO) after drainage
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on ascending cholangitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For ascending cholangitis in a patient tolerant of penicillin but intolerant of gentamicin:

Code for piperacillin or ceftriaxone is: 3asc

This code is valid for THREE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 72 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• If patient appears septic, treat as per severe sepsis protocol (see homepage)
• Consider an early switch to oral within 48 hours as with all abdominal infections
• Total antibiotic therapy for patients who have not undergone biliary drainage, is 7-10 days (IV and PO). For patients who have undergone biliary drainage, total antibiotic therapy is 5 days (IV and PO) after drainage
• Ascending cholangitis is usually caused by enteric gram negative bacilli such as Eschericia.coli, Klebsiella spp and Enterobacter spp. Gram positive bacteria such as Enterococcus may also be implicated. Infrequently it is caused by anaerobic bacteria

References:

See section on ascending cholangitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

If the patient tolerates penicillin treat with:

Code for gentamicin is: 2liv

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• In children, liver abscesses are rare and most commonly caused by Staphylococcus aureus. Seek expert paediatric advice for management—it may be necessary to involve a multidisciplinary team, including a paediatric infectious diseases physician
• Drainage is the mainstay of therapy for the treatment of bacterial liver abscess. For abscesses less than 5 cm in diameter, closed-needle drainage is usually sufficient. For abscesses more than 5 cm in diameter, radiologically guided catheter drainage is recommended. Surgical drainage is needed in more complicated situations, including multiple or loculated abscesses, and for cases with inadequate response to catheter drainage and antibiotics after 7 days
• Drainage is rarely necessary for the treatment of amoebic liver abscess
• Modify therapy based on the results of culture and susceptibility testing, if available. If the results of susceptibility testing are not available by 72 hours and empirical intravenous therapy is still required
• The total duration of therapy is usually 4 to 6 weeks (intravenous + oral). If response to initial drainage is good, switch to directed oral therapy after 2 weeks. If results of culture and susceptibility testing are not available, a reasonable oral option is amoxicillin+clavulanate. If drainage was incomplete, 4 to 6 weeks of intravenous antibiotic therapy may be required
• The presentation of bacterial and amoebic liver abscess can be identical, so in all cases, take blood samples for culture and susceptibility testing (for bacterial causes) and serological testing (for E. histolytica). Ultrasound- or computed tomography (CT)–guided needle aspiration of the abscess, together with microbiological examination of the aspirate, is usually necessary for diagnosis. If radiological imaging suggests hydatid disease, needle aspiration should be delayed to avoid intraperitoneal spillage of hydatid contents—seek expert advice
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Paediatric Gentamicin Dosing (Age < 12 years)

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• For dosing in children with cystic fibrosis or those receiving chemotherapy, seek expert advice
• For children with impaired renal function (estimated glomerular filtration rate [eGFR] less than 50 mL/min/1.73 m²), give a single dose, then seek expert advice for subsequent dosing or selection of alternative drug. Use the modified Schwartz formula to estimate GFR
• Postmenstrual age is the time elapsed between the first day of the last menstrual period and birth (gestational age) plus the time elapsed after birth (postnatal age)
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on liver abscess - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient has a non-severe penicillin allergy treat with:

Code for ceftriaxone or cefotaxime is: 2liv

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• In children, liver abscesses are rare and most commonly caused by Staphylococcus aureus. Seek expert paediatric advice for management—it may be necessary to involve a multidisciplinary team, including a paediatric infectious diseases physician
• Drainage is the mainstay of therapy for the treatment of bacterial liver abscess. For abscesses less than 5 cm in diameter, closed-needle drainage is usually sufficient. For abscesses more than 5 cm in diameter, radiologically guided catheter drainage is recommended. Surgical drainage is needed in more complicated situations, including multiple or loculated abscesses, and for cases with inadequate response to catheter drainage and antibiotics after 7 days
• Drainage is rarely necessary for the treatment of amoebic liver abscess
• Modify therapy based on the results of culture and susceptibility testing, if available. If the results of susceptibility testing are not available by 72 hours and empirical intravenous therapy is still required
• The total duration of therapy is usually 4 to 6 weeks (intravenous + oral). If response to initial drainage is good, switch to directed oral therapy after 2 weeks. If drainage was incomplete, 4 to 6 weeks of intravenous antibiotic therapy may be required
• The presentation of bacterial and amoebic liver abscess can be identical, so in all cases, take blood samples for culture and susceptibility testing (for bacterial causes) and serological testing (for E. histolytica). Ultrasound- or computed tomography (CT)–guided needle aspiration of the abscess, together with microbiological examination of the aspirate, is usually necessary for diagnosis. If radiological imaging suggests hydatid disease, needle aspiration should be delayed to avoid intraperitoneal spillage of hydatid contents—seek expert advice

References:

See section on liver abscess - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient has a severe penicillin allergy:

Treatment options are limited. Treatment options include metronidazole in combination with either gentamicin, ciprofloxacin or aztreonam. Please contact infectious diseases for advice

• In children, liver abscesses are rare and most commonly caused by Staphylococcus aureus. Seek expert paediatric advice for management—it may be necessary to involve a multidisciplinary team, including a paediatric infectious diseases physician
• Drainage is the mainstay of therapy for the treatment of bacterial liver abscess. For abscesses less than 5 cm in diameter, closed-needle drainage is usually sufficient. For abscesses more than 5 cm in diameter, radiologically guided catheter drainage is recommended. Surgical drainage is needed in more complicated situations, including multiple or loculated abscesses, and for cases with inadequate response to catheter drainage and antibiotics after 7 days
• Drainage is rarely necessary for the treatment of amoebic liver abscess
• Modify therapy based on the results of culture and susceptibility testing, if available. If the results of susceptibility testing are not available by 72 hours and empirical intravenous therapy is still required
• The total duration of therapy is usually 4 to 6 weeks (intravenous + oral). If response to initial drainage is good, switch to directed oral therapy after 2 weeks. If drainage was incomplete, 4 to 6 weeks of intravenous antibiotic therapy may be required
• The presentation of bacterial and amoebic liver abscess can be identical, so in all cases, take blood samples for culture and susceptibility testing (for bacterial causes) and serological testing (for E. histolytica). Ultrasound- or computed tomography (CT)–guided needle aspiration of the abscess, together with microbiological examination of the aspirate, is usually necessary for diagnosis. If radiological imaging suggests hydatid disease, needle aspiration should be delayed to avoid intraperitoneal spillage of hydatid contents—seek expert advice

References:

See section on liver abscess - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

Is the postpartum endometritis severe or non-severe? Postpartum endometritis is considered nonsevere if the infection is localised and the patient does not have fever or other systemic features. If the patient has any systemic features treat as severe.

• Non-severe infection
• Severe infection

Is the postpartum endometritis severe or non-severe? Postpartum endometritis is considered nonsevere if the infection is localised and the patient does not have fever or other systemic features. If the patient has any systemic features treat as severe.

• Non-severe infection
• Severe infection

Is the postpartum endometritis severe or non-severe? Postpartum endometritis is considered nonsevere if the infection is localised and the patient does not have fever or other systemic features. If the patient has any systemic features treat as severe.

• Non-severe infection
• Severe infection

For non-severe endometritis with no penicillin allergy give:

• Postpartum endometritis typically presents with fever (38°C or more), lower abdominal pain and uterine tenderness. Purulent vaginal discharge may be present
• The majority of endometritis cases present within the first week after delivery, but approximately 15% of cases present between 1 and 6 weeks postpartum. Late presentations are often less severe and may present as late postpartum haemorrhage. If postpartum endometritis is suspected, refer to an obstetrician for appropriate assessment and management
• Modify therapy based on the results of culture and susceptibility testing (if possible), and clinical response
• Postpartum endometritis is usually a polymicrobial infection, most commonly involving ascending cervicovaginal organisms. Rarely, patients who are critically ill with sepsis or septic shock may have infection caused by Clostridium species or Streptococcus pyogenes (group A Streptococcus). Late-onset endometritis (occurring more than 7 days after delivery) suggests Chlamydia trachomatis infection

References:

See section on postpartum endometritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For non-severe endometritis with a penicillin allergy give:

• Postpartum endometritis typically presents with fever (38°C or more), lower abdominal pain and uterine tenderness. Purulent vaginal discharge may be present
• The majority of endometritis cases present within the first week after delivery, but approximately 15% of cases present between 1 and 6 weeks postpartum. Late presentations are often less severe and may present as late postpartum haemorrhage. If postpartum endometritis is suspected, refer to an obstetrician for appropriate assessment and management
• Modify therapy based on the results of culture and susceptibility testing (if possible), and clinical response
• Postpartum endometritis is usually a polymicrobial infection, most commonly involving ascending cervicovaginal organisms. Rarely, patients who are critically ill with sepsis or septic shock may have infection caused by Clostridium species or Streptococcus pyogenes (group A Streptococcus). Late-onset endometritis (occurring more than 7 days after delivery) suggests Chlamydia trachomatis infection

References:

See section on postpartum endometritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Is gentamicin contraindicated in this patient? (See below)

• No gentamicin contraindications
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below)

• No gentamicin contraindications
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below)

• No gentamicin contraindications
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is the patient's Group B Streptococcus isolate susceptible to clindamycin?

• Group B Streptococcus status unknown
• Group B Streptococcus clindamycin sensitive
• Group B Streptococcus clindamycin resistant

• If the patient Group B Streptococcus sensitivity is pending then treat as 'status unknown'

For severe endometritis with no penicillin allergy give:

Code for gentamicin is: 2end

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Modify therapy based on the results of culture and susceptibility testing (if possible), and clinical response. If results of susceptibility testing are not available by 72 hours and empirical intravenous therapy is still required, stop the gentamicin-containing regimen and seek expert advice
• For uncomplicated infections, continue intravenous antibiotic therapy for at least 24 to 48 hours after the resolution of leucocytosis and clinical signs and symptoms (ie fever, uterine tenderness, purulent vaginal discharge), and then stop antibiotic therapy. Oral antibiotic therapy is not required
• For complicated infection (eg abscess, bacteraemia), a longer course of intravenous therapy may be required followed by a switch to oral therapy once the patient is clinically stable (see Therapeutic Guidelines for Guidance for antimicrobial intravenous to oral switch). If the results of susceptibility testing are not available and oral continuation therapy is appropriate, use oral therapy as for nonsevere postpartum endometritis
• Postpartum endometritis typically presents with fever (38°C or more), lower abdominal pain and uterine tenderness. Purulent vaginal discharge may be present
• The majority of endometritis cases present within the first week after delivery, but approximately 15% of cases present between 1 and 6 weeks postpartum. Late presentations are often less severe and may present as late postpartum haemorrhage. If postpartum endometritis is suspected, refer to an obstetrician for appropriate assessment and management
• Postpartum endometritis is usually a polymicrobial infection, most commonly involving ascending cervicovaginal organisms. Rarely, patients who are critically ill with sepsis or septic shock may have infection caused by Clostridium species or Streptococcus pyogenes (group A Streptococcus). Late-onset endometritis (occurring more than 7 days after delivery) suggests Chlamydia trachomatis infection

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on postpartum endometritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For severe endometritis with non-severe penicillin allergy give:

Code for gentamicin is: 2end

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Modify therapy based on the results of culture and susceptibility testing (if possible), and clinical response. If results of susceptibility testing are not available by 72 hours and empirical intravenous therapy is still required, stop the gentamicin-containing regimen and seek expert advice
• For uncomplicated infections, continue intravenous antibiotic therapy for at least 24 to 48 hours after the resolution of leucocytosis and clinical signs and symptoms (ie fever, uterine tenderness, purulent vaginal discharge), and then stop antibiotic therapy. Oral antibiotic therapy is not required
• For complicated infection (eg abscess, bacteraemia), a longer course of intravenous therapy may be required followed by a switch to oral therapy once the patient is clinically stable (see Therapeutic Guidelines for Guidance for antimicrobial intravenous to oral switch). If the results of susceptibility testing are not available and oral continuation therapy is appropriate, use oral therapy as for nonsevere postpartum endometritis
• Postpartum endometritis typically presents with fever (38°C or more), lower abdominal pain and uterine tenderness. Purulent vaginal discharge may be present
• The majority of endometritis cases present within the first week after delivery, but approximately 15% of cases present between 1 and 6 weeks postpartum. Late presentations are often less severe and may present as late postpartum haemorrhage. If postpartum endometritis is suspected, refer to an obstetrician for appropriate assessment and management
• Postpartum endometritis is usually a polymicrobial infection, most commonly involving ascending cervicovaginal organisms. Rarely, patients who are critically ill with sepsis or septic shock may have infection caused by Clostridium species or Streptococcus pyogenes (group A Streptococcus). Late-onset endometritis (occurring more than 7 days after delivery) suggests Chlamydia trachomatis infection

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on postpartum endometritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If gentamicin is contraindicated:

• Modify therapy based on the results of culture and susceptibility testing (if possible), and clinical response
• For uncomplicated infections, continue intravenous antibiotic therapy for at least 24 to 48 hours after the resolution of leucocytosis and clinical signs and symptoms (ie fever, uterine tenderness, purulent vaginal discharge), and then stop antibiotic therapy. Oral antibiotic therapy is not required
• For complicated infection (eg abscess, bacteraemia), a longer course of intravenous therapy may be required followed by a switch to oral therapy once the patient is clinically stable (see Therapeutic Guidelines for Guidance for antimicrobial intravenous to oral switch). If the results of susceptibility testing are not available and oral continuation therapy is appropriate, use oral therapy as for nonsevere postpartum endometritis
• Postpartum endometritis typically presents with fever (38°C or more), lower abdominal pain and uterine tenderness. Purulent vaginal discharge may be present
• The majority of endometritis cases present within the first week after delivery, but approximately 15% of cases present between 1 and 6 weeks postpartum. Late presentations are often less severe and may present as late postpartum haemorrhage. If postpartum endometritis is suspected, refer to an obstetrician for appropriate assessment and management
• Postpartum endometritis is usually a polymicrobial infection, most commonly involving ascending cervicovaginal organisms. Rarely, patients who are critically ill with sepsis or septic shock may have infection caused by Clostridium species or Streptococcus pyogenes (group A Streptococcus). Late-onset endometritis (occurring more than 7 days after delivery) suggests Chlamydia trachomatis infection

References:

See section on postpartum endometritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For severe endometritis with severe penicillin allergy and either resistant Group B Streptococcus or unable to tolerate gentamicin give:

Code for vancomycin is: 3end

This code is valid for THREE days only. Starting from the first day of treatment for this condition. Infectious diseases must be contacted within 72 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Modify therapy based on the results of culture and susceptibility testing (if possible), and clinical response
• For uncomplicated infections, continue intravenous antibiotic therapy for at least 24 to 48 hours after the resolution of leucocytosis and clinical signs and symptoms (ie fever, uterine tenderness, purulent vaginal discharge), and then stop antibiotic therapy. Oral antibiotic therapy is not required
• For complicated infection (eg abscess, bacteraemia), a longer course of intravenous therapy may be required followed by a switch to oral therapy once the patient is clinically stable (see Therapeutic Guidelines for Guidance for antimicrobial intravenous to oral switch). If the results of susceptibility testing are not available and oral continuation therapy is appropriate, use oral therapy as for nonsevere postpartum endometritis
• Postpartum endometritis typically presents with fever (38°C or more), lower abdominal pain and uterine tenderness. Purulent vaginal discharge may be present
• The majority of endometritis cases present within the first week after delivery, but approximately 15% of cases present between 1 and 6 weeks postpartum. Late presentations are often less severe and may present as late postpartum haemorrhage. If postpartum endometritis is suspected, refer to an obstetrician for appropriate assessment and management
• Postpartum endometritis is usually a polymicrobial infection, most commonly involving ascending cervicovaginal organisms. Rarely, patients who are critically ill with sepsis or septic shock may have infection caused by Clostridium species or Streptococcus pyogenes (group A Streptococcus). Late-onset endometritis (occurring more than 7 days after delivery) suggests Chlamydia trachomatis infection

Vancomycin Dosing in Adults

1. Vancomycin should be administered at a maximum rate of 10 mg/min to avoid Red Person Syndrome
2. "Trough" levels are taken within 60 minutes of the next dose. If a loading dose is given then it is considered the first dose
3. In patients with CrClr < 20 mL/min, the clinical context (e.g haemodialysis) determines whether the next dose is given before the trough concentration is available or withheld until the result is known

• Please contact infectious diseases within 48 hours of initiating therapy with vancomycin
• Please contact infectious diseases for any patient with a body mass index [BMI] of 30 kg/m² or more, dosing is complex in obese patients
• Watch baseline creatinine closely while treating a patient with vancomycin. An increase from baseline creatinine will almost always result in an increase in vancomycin concentration as vancomycin is 40-100% renally cleared. A sudden dramatic increase in creatinine should always prompt an immediate vancomycin level prior to the next dose, witholding the next dose until the level is available
• If a dose is missed or delayed within 48 hours of taking a level please contact pharmacy for interpretation of trough levels as vancomycin will not have reached steady state

References:

See section on postpartum endometritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For severe endometritis with severe penicillin allergy tolerant of gentamicin with Group B Streptococcus sensitive to clindamycin give:

Code for gentamicin and clindamycin IV is: 2end

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Modify therapy based on the results of culture and susceptibility testing (if possible), and clinical response. If results of susceptibility testing are not available by 72 hours and empirical intravenous therapy is still required, stop the gentamicin-containing regimen and seek expert advice
• For uncomplicated infections, continue intravenous antibiotic therapy for at least 24 to 48 hours after the resolution of leucocytosis and clinical signs and symptoms (ie fever, uterine tenderness, purulent vaginal discharge), and then stop antibiotic therapy. Oral antibiotic therapy is not required
• For complicated infection (eg abscess, bacteraemia), a longer course of intravenous therapy may be required followed by a switch to oral therapy once the patient is clinically stable (see Therapeutic Guidelines for Guidance for antimicrobial intravenous to oral switch). If the results of susceptibility testing are not available and oral continuation therapy is appropriate, use oral therapy as for nonsevere postpartum endometritis
• Postpartum endometritis typically presents with fever (38°C or more), lower abdominal pain and uterine tenderness. Purulent vaginal discharge may be present
• The majority of endometritis cases present within the first week after delivery, but approximately 15% of cases present between 1 and 6 weeks postpartum. Late presentations are often less severe and may present as late postpartum haemorrhage. If postpartum endometritis is suspected, refer to an obstetrician for appropriate assessment and management
• Postpartum endometritis is usually a polymicrobial infection, most commonly involving ascending cervicovaginal organisms. Rarely, patients who are critically ill with sepsis or septic shock may have infection caused by Clostridium species or Streptococcus pyogenes (group A Streptococcus). Late-onset endometritis (occurring more than 7 days after delivery) suggests Chlamydia trachomatis infection

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on postpartum endometritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

Does the patient have severe infection or are they showing signs of severe sepsis? (See below)

• Yes
• No

Signs of Sepsis:

• See the Therapeutic Guidelines for more advice on managing a septic patient
• If yes to the above contact an ID physician for review of this patient

Does the patient have severe infection or are they showing signs of severe sepsis? (See below)

• Yes
• No

Signs of Sepsis:

• See the Therapeutic Guidelines for more advice on managing a septic patient
• If yes to the above contact an ID physician for review of this patient

Does the patient have severe infection or are they showing signs of severe sepsis? (See below)

• Yes
• No

Signs of Sepsis:

• See the Therapeutic Guidelines for more advice on managing a septic patient
• If yes to the above contact an ID physician for review of this patient

Is gentamicin contraindicated in this patient? (See below)

• No gentamicin contraindications
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below)

• No gentamicin contraindications
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below)

• No gentamicin contraindications
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

For chorioamnionitis treatment with no penicillin allergy but with gentamicin contraindications:

Code for IV Amoxicillin+Clavulanate, piperacillin+tazobactam or ceftriaxone is: 3chr

This code is valid for THREE days only. Starting from the first day of treatment for this condition. Infectious diseases must be contacted within 72 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Women with intra-amniotic infections often present with nonspecific signs of infection. Suspect intra-amniotic infection in a pregnant woman with any of the following features:
  • fever (38°C or more) and ruptured membranes
  • fever during labour (intrapartum fever), even if membranes are intact
  • uterine tenderness
  • purulent amniotic fluid
• If intra-amniotic infection is suspected, early consultation with an obstetrician is required for appropriate assessment and management
• Patients undergoing caesarean section require surgical prophylaxis (see here for regimens). If the intra-amniotic infection treatment regimen has an appropriate spectrum of activity for prophylaxis, additional surgical prophylaxis is not required. However, adjust the timing of the dose to achieve adequate plasma and tissue concentrations at the time of surgical incision and for the duration of the procedure
• If the results of culture and susceptibility testing are not available by 72 hours and empirical therapy is still required seek specialist advice
• Neonates born to mothers with intra-amniotic infection are at increased risk of early-onset sepsis. Following birth, closely observe neonates born to mothers with intrapartum fever (ie 38°C or more during labour), or suspected or confirmed intra-amniotic infection

References:

See section on sepsis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For chorioamnionitis treatment with no penicillin allergy or gentamicin contraindications:

Code for gentamicin is: 2chr

This code is valid for TWO days only. Starting from the first day of treatment for this condition. Infectious diseases must be contacted within 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Women with intra-amniotic infections often present with nonspecific signs of infection. Suspect intra-amniotic infection in a pregnant woman with any of the following features:
  • fever (38°C or more) and ruptured membranes
  • fever during labour (intrapartum fever), even if membranes are intact
  • uterine tenderness
  • purulent amniotic fluid
• If intra-amniotic infection is suspected, early consultation with an obstetrician is required for appropriate assessment and management
• Patients undergoing caesarean section require surgical prophylaxis (see here for regimens). If the intra-amniotic infection treatment regimen has an appropriate spectrum of activity for prophylaxis, additional surgical prophylaxis is not required. However, adjust the timing of the dose to achieve adequate plasma and tissue concentrations at the time of surgical incision and for the duration of the procedure
• If the results of culture and susceptibility testing are not available by 72 hours and empirical therapy is still required seek specialist advice
• Neonates born to mothers with intra-amniotic infection are at increased risk of early-onset sepsis. Following birth, closely observe neonates born to mothers with intrapartum fever (ie 38°C or more during labour), or suspected or confirmed intra-amniotic infection

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on chorioamnionitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For chorioamnionitis with non-severe penicillin allergy and gentamicin contraindications give:

Code for ceftriaxone is: 3chr

This code is valid for THREE days only. Starting from the first day of treatment for this condition. Infectious diseases must be contacted within 72 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Women with intra-amniotic infections often present with nonspecific signs of infection. Suspect intra-amniotic infection in a pregnant woman with any of the following features:
  • fever (38°C or more) and ruptured membranes
  • fever during labour (intrapartum fever), even if membranes are intact
  • uterine tenderness
  • purulent amniotic fluid
• If intra-amniotic infection is suspected, early consultation with an obstetrician is required for appropriate assessment and management
• Patients undergoing caesarean section require surgical prophylaxis (see here for regimens). If the intra-amniotic infection treatment regimen has an appropriate spectrum of activity for prophylaxis, additional surgical prophylaxis is not required. However, adjust the timing of the dose to achieve adequate plasma and tissue concentrations at the time of surgical incision and for the duration of the procedure
• If the results of culture and susceptibility testing are not available by 72 hours and empirical therapy is still required seek specialist advice
• Neonates born to mothers with intra-amniotic infection are at increased risk of early-onset sepsis. Following birth, closely observe neonates born to mothers with intrapartum fever (ie 38°C or more during labour), or suspected or confirmed intra-amniotic infection

References:

See section on chorioamnionitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For chorioamnionitis with non-severe immediate or delayed penicillin hypersensitivity give:

Code for gentamicin is: 2chr

This code is valid for TWO days only. Starting from the first day of treatment for this condition. Infectious diseases must be contacted within 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Women with intra-amniotic infections often present with nonspecific signs of infection. Suspect intra-amniotic infection in a pregnant woman with any of the following features:
  • fever (38°C or more) and ruptured membranes
  • fever during labour (intrapartum fever), even if membranes are intact
  • uterine tenderness
  • purulent amniotic fluid
• If intra-amniotic infection is suspected, early consultation with an obstetrician is required for appropriate assessment and management
• Patients undergoing caesarean section require surgical prophylaxis (see here for regimens). If the intra-amniotic infection treatment regimen has an appropriate spectrum of activity for prophylaxis, additional surgical prophylaxis is not required. However, adjust the timing of the dose to achieve adequate plasma and tissue concentrations at the time of surgical incision and for the duration of the procedure
• If the results of culture and susceptibility testing are not available by 72 hours and empirical therapy is still required seek specialist advice
• Neonates born to mothers with intra-amniotic infection are at increased risk of early-onset sepsis. Following birth, closely observe neonates born to mothers with intrapartum fever (ie 38°C or more during labour), or suspected or confirmed intra-amniotic infection

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on chorioamnionitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For chorioamnionitis with severe immediate or delayed penicillin hypersensitivity give:

Code for IV clindamycin, vancomycin and gentamicin is: 2chr

This code is valid for TWO days only. Starting from the first day of treatment for this condition. Infectious diseases must be contacted within 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Women with intra-amniotic infections often present with nonspecific signs of infection. Suspect intra-amniotic infection in a pregnant woman with any of the following features:
  • fever (38°C or more) and ruptured membranes
  • fever during labour (intrapartum fever), even if membranes are intact
  • uterine tenderness
  • purulent amniotic fluid
• If intra-amniotic infection is suspected, early consultation with an obstetrician is required for appropriate assessment and management
• Patients undergoing caesarean section require surgical prophylaxis (see here for regimens). If the intra-amniotic infection treatment regimen has an appropriate spectrum of activity for prophylaxis, additional surgical prophylaxis is not required. However, adjust the timing of the dose to achieve adequate plasma and tissue concentrations at the time of surgical incision and for the duration of the procedure
• If the results of culture and susceptibility testing are not available by 72 hours and empirical therapy is still required seek specialist advice
• Neonates born to mothers with intra-amniotic infection are at increased risk of early-onset sepsis. Following birth, closely observe neonates born to mothers with intrapartum fever (ie 38°C or more during labour), or suspected or confirmed intra-amniotic infection

Vancomycin Dosing in Adults

1. Vancomycin should be administered at a maximum rate of 10 mg/min to avoid Red Person Syndrome
2. "Trough" levels are taken within 60 minutes of the next dose. If a loading dose is given then it is considered the first dose
3. In patients with CrClr < 20 mL/min, the clinical context (e.g haemodialysis) determines whether the next dose is given before the trough concentration is available or withheld until the result is known

• Please contact infectious diseases within 48 hours of initiating therapy with vancomycin
• Please contact infectious diseases for any patient with a body mass index [BMI] of 30 kg/m² or more, dosing is complex in obese patients
• Watch baseline creatinine closely while treating a patient with vancomycin. An increase from baseline creatinine will almost always result in an increase in vancomycin concentration as vancomycin is 40-100% renally cleared. A sudden dramatic increase in creatinine should always prompt an immediate vancomycin level prior to the next dose, witholding the next dose until the level is available
• If a dose is missed or delayed within 48 hours of taking a level please contact pharmacy for interpretation of trough levels as vancomycin will not have reached steady state

References:

See section on chorioamnionitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If gentamicin is contraindicated:

• Women with intra-amniotic infections often present with nonspecific signs of infection. Suspect intra-amniotic infection in a pregnant woman with any of the following features:
  • fever (38°C or more) and ruptured membranes
  • fever during labour (intrapartum fever), even if membranes are intact
  • uterine tenderness
  • purulent amniotic fluid
• If intra-amniotic infection is suspected, early consultation with an obstetrician is required for appropriate assessment and management
• Patients undergoing caesarean section require surgical prophylaxis (see here for regimens). If the intra-amniotic infection treatment regimen has an appropriate spectrum of activity for prophylaxis, additional surgical prophylaxis is not required. However, adjust the timing of the dose to achieve adequate plasma and tissue concentrations at the time of surgical incision and for the duration of the procedure
• If the results of culture and susceptibility testing are not available by 72 hours and empirical therapy is still required seek specialist advice
• Neonates born to mothers with intra-amniotic infection are at increased risk of early-onset sepsis. Following birth, closely observe neonates born to mothers with intrapartum fever (ie 38°C or more during labour), or suspected or confirmed intra-amniotic infection

Does the patient have features of severe disease? (See below)

• Yes
• No

Is the patient immunocompromised?

• Yes
• No

Can the patient tolerate oral antibiotics? (See below)

• Yes
• No

• Oral antibiotics are the preferred route of administration for bacterial enteritis due to superior local action within the GI tract versus intravenous therapy

Low risk gastroenteritis:

• Send stool for microscopy, culture and sensitivities in all patients who have features of severe disease (such as high fever, tachycardia, leucocytosis, abdominal tenderness or severe abdominal pain, high-volume diarrhoea with hypovolaemia, blood in the stool)
• In immunocompromised patients, in addition to sending stool for routine pathogens, request microscopy for ova, cysts and parasites, and consider testing for cytomegalovirus
• In returned travellers from high risk areas, request testing for Salmonella Typhi and Paratyphi and discuss treatment with infectious diseases
• In patients with recent hospitalisation or antibiotic use, request testing for Clostridium difficile and consider empiric treatment for C. difficile
• In infants, bacterial enteritis is treated more aggressively with antibiotics due to the greater risk of developing severe sepsis. Seek expert advice for all infant enteritis cases
• If the results of microbiological testing are available before the symptoms of diarrhoea have resolved, adjust therapy accordingly
• The principal aim of treatment of acute infectious diarrhoea is to achieve and maintain adequate hydration. All patients with gastroenteritis should have their hydration status assessed and appropriate fluid resuscitation given

Is the patient an adult or child?

• Adult
• Child

Does the patient have risk factors for enterohaemorrhagic E.coli? (See below)

• Yes, bloody stool without fever
• No

• Antibiotic therapy is not recommended in children with bloody diarrhoea without fever, due to the potential for precipitating haemolytic uraemic syndrome if the infection is caused by enterohaemorrhagic Escherichia coli

Can the patient tolerate oral antibiotics? (See below)

• Yes
• No

• Oral antibiotics are the preferred route of administration for bacterial enteritis due to superior local action within the GI tract versus intravenous therapy

Can the patient tolerate oral antibiotics? (See below)

• Yes
• No

• Oral antibiotics are the preferred route of administration for bacterial enteritis due to superior local action within the GI tract versus intravenous therapy

Has the patient had a life-threatening reaction or anaphylaxis to a penicillin antibiotic or do they have a cephalosporin allergy? (See below)

• no allergy, or immediate non-severe or delayed non-severe penicillin hypersensitivity and no cephalosporin allergy
• Life-Threatening reaction or anaphylaxis to penicillin or cephalosporin allergy

Diagnostic Criteria for Penicillin Allergy:

• Non-life threatening reactions such as minor rash, skin irritation, nausea, diarrhoea or vomiting should not usually be considered life threatening and may not be an allergic reaction at all
• There is only a 2.5% chance of cephalosporin allergy in a patient previously allergic to penicillin. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin
• Life-threatening reactions include SJS, DRESS, TENS or any reaction that led to respiratory compromise

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

Has the patient had a life-threatening reaction or anaphylaxis to a penicillin antibiotic or do they have a cephalosporin allergy? (See below)

• no allergy, or immediate non-severe or delayed non-severe penicillin hypersensitivity and no cephalosporin allergy
• Life-Threatening reaction or anaphylaxis to penicillin or cephalosporin allergy

Diagnostic Criteria for Penicillin Allergy:

• Non-life threatening reactions such as minor rash, skin irritation, nausea, diarrhoea or vomiting should not usually be considered life threatening and may not be an allergic reaction at all
• There is only a 2.5% chance of cephalosporin allergy in a patient previously allergic to penicillin. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin
• Life-threatening reactions include SJS, DRESS, TENS or any reaction that led to respiratory compromise

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

Has the patient had a life-threatening reaction or anaphylaxis to a penicillin antibiotic or do they have a cephalosporin allergy? (See below)

• no allergy, or immediate non-severe or delayed non-severe penicillin hypersensitivity and no cephalosporin allergy
• Life-Threatening reaction or anaphylaxis to penicillin or cephalosporin allergy

Diagnostic Criteria for Penicillin Allergy:

• Non-life threatening reactions such as minor rash, skin irritation, nausea, diarrhoea or vomiting should not usually be considered life threatening and may not be an allergic reaction at all
• There is only a 2.5% chance of cephalosporin allergy in a patient previously allergic to penicillin. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin
• Life-threatening reactions include SJS, DRESS, TENS or any reaction that led to respiratory compromise

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

If the patient can tolerate oral therapy give:

Code for azithromycin orally is: 3gas

This code is valid for THREE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if treatment is to continue past 72 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• In infants, bacterial enteritis is treated more aggressively with antibiotics due to the greater risk of developing severe sepsis. Seek expert advice for all infant enteritis cases
• If the results of microbiological testing are available before the symptoms of diarrhoea have resolved, adjust therapy accordingly
• The principal aim of treatment of acute infectious diarrhoea is to achieve and maintain adequate hydration. All patients with gastroenteritis should have their hydration status assessed so that appropriate rehydration can be given
• The usually self-limiting nature of acute infectious diarrhoea means that there is rarely a need for microbiological testing or antimicrobial therapy
• Faecal microbiological testing, when performed, rarely provides results during the acute stages of gastroenteritis. Perform testing in all patients who have features of severe disease (such as high fever, tachycardia, leucocytosis, abdominal tenderness or severe abdominal pain, high-volume diarrhoea with hypovolaemia, blood in the stool)

References:

See section on gastroenteritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient cannot tolerate oral therapy give:

Code for ceftriaxone is: 3gas

This code is valid for THREE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if treatment is to continue past 72 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Send stool for microscopy, culture and sensitivities in all patients who have features of severe disease (such as high fever, tachycardia, leucocytosis, abdominal tenderness or severe abdominal pain, high-volume diarrhoea with hypovolaemia, blood in the stool)
• In immunocompromised patients, in addition to sending stool for routine pathogens, request microscopy for ova, cysts and parasites, and consider testing for cytomegalovirus
• In returned travellers from high risk areas, request testing for Salmonella Typhi and Paratyphi and discuss treatment with infectious diseases
• In patients with recent hospitalisation or antibiotic use, request testing for Clostridium difficile and consider empiric treatment for C. difficile
• In infants, bacterial enteritis is treated more aggressively with antibiotics due to the greater risk of developing severe sepsis. Seek expert advice for all infant enteritis cases
• If the results of microbiological testing are available before the symptoms of diarrhoea have resolved, adjust therapy accordingly
• The principal aim of treatment of acute infectious diarrhoea is to achieve and maintain adequate hydration. All patients with gastroenteritis should have their hydration status assessed and appropriate fluid resuscitation given

References:

See section on gastroenteritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient can tolerate oral therapy give:

Code for ciprofloxacin orally, norfloxacin or azithromycin orally is: 3gas

This code is valid for THREE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if treatment is to continue past 72 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Send stool for microscopy, culture and sensitivities in all patients who have features of severe disease (such as high fever, tachycardia, leucocytosis, abdominal tenderness or severe abdominal pain, high-volume diarrhoea with hypovolaemia, blood in the stool)
• In immunocompromised patients, in addition to sending stool for routine pathogens, request microscopy for ova, cysts and parasites, and consider testing for cytomegalovirus
• In returned travellers from high risk areas, request testing for Salmonella Typhi and Paratyphi and discuss treatment with infectious diseases
• In patients with recent hospitalisation or antibiotic use, request testing for Clostridium difficile and consider empiric treatment for C. difficile
• In infants, bacterial enteritis is treated more aggressively with antibiotics due to the greater risk of developing severe sepsis. Seek expert advice for all infant enteritis cases
• If the results of microbiological testing are available before the symptoms of diarrhoea have resolved, adjust therapy accordingly
• The principal aim of treatment of acute infectious diarrhoea is to achieve and maintain adequate hydration. All patients with gastroenteritis should have their hydration status assessed and appropriate fluid resuscitation given

References:

See section on gastroenteritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient can tolerate oral therapy and bacterial infection is suspected consider giving:

Code for ciprofloxacin orally, norfloxacin or azithromycin orally is: 3gas

This code is valid for THREE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if treatment is to continue past 72 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Send stool for microscopy, culture and sensitivities in all patients who have features of severe disease (such as high fever, tachycardia, leucocytosis, abdominal tenderness or severe abdominal pain, high-volume diarrhoea with hypovolaemia, blood in the stool)
• In immunocompromised patients, in addition to sending stool for routine pathogens, request microscopy for ova, cysts and parasites, and consider testing for cytomegalovirus
• In returned travellers from high risk areas, request testing for Salmonella Typhi and Paratyphi and discuss treatment with infectious diseases
• In patients with recent hospitalisation or antibiotic use, request testing for Clostridium difficile and consider empiric treatment for C. difficile
• In infants, bacterial enteritis is treated more aggressively with antibiotics due to the greater risk of developing severe sepsis. Seek expert advice for all infant enteritis cases
• If the results of microbiological testing are available before the symptoms of diarrhoea have resolved, adjust therapy accordingly
• The principal aim of treatment of acute infectious diarrhoea is to achieve and maintain adequate hydration. All patients with gastroenteritis should have their hydration status assessed and appropriate fluid resuscitation given

References:

See section on gastroenteritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient cannot tolerate oral therapy give:

Code for ceftriaxone or cefotaxime is: 3gas

This code is valid for THREE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if treatment is to continue past 72 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Send stool for microscopy, culture and sensitivities in all patients who have features of severe disease (such as high fever, tachycardia, leucocytosis, abdominal tenderness or severe abdominal pain, high-volume diarrhoea with hypovolaemia, blood in the stool)
• In immunocompromised patients, in addition to sending stool for routine pathogens, request microscopy for ova, cysts and parasites, and consider testing for cytomegalovirus
• In returned travellers from high risk areas, request testing for Salmonella Typhi and Paratyphi and discuss treatment with infectious diseases
• In patients with recent hospitalisation or antibiotic use, request testing for Clostridium difficile and consider empiric treatment for C. difficile
• In infants, bacterial enteritis is treated more aggressively with antibiotics due to the greater risk of developing severe sepsis. Seek expert advice for all infant enteritis cases
• If the results of microbiological testing are available before the symptoms of diarrhoea have resolved, adjust therapy accordingly
• The principal aim of treatment of acute infectious diarrhoea is to achieve and maintain adequate hydration. All patients with gastroenteritis should have their hydration status assessed and appropriate fluid resuscitation given

References:

See section on gastroenteritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient has a history of penicillin anaphylaxis and cannot tolerate oral medications:

• Send stool for microscopy, culture and sensitivities in all patients who have features of severe disease (such as high fever, tachycardia, leucocytosis, abdominal tenderness or severe abdominal pain, high-volume diarrhoea with hypovolaemia, blood in the stool)
• In immunocompromised patients, in addition to sending stool for routine pathogens, request microscopy for ova, cysts and parasites, and consider testing for cytomegalovirus
• In returned travellers from high risk areas, request testing for Salmonella Typhi and Paratyphi and discuss treatment with infectious diseases
• In patients with recent hospitalisation or antibiotic use, request testing for Clostridium difficile and consider empiric treatment for C. difficile
• In infants, bacterial enteritis is treated more aggressively with antibiotics due to the greater risk of developing severe sepsis. Seek expert advice for all infant enteritis cases
• If the results of microbiological testing are available before the symptoms of diarrhoea have resolved, adjust therapy accordingly
• The principal aim of treatment of acute infectious diarrhoea is to achieve and maintain adequate hydration. All patients with gastroenteritis should have their hydration status assessed and appropriate fluid resuscitation given

References:

See section on gastroenteritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient has risk factors for enterohaemorrhagic E.coli then antibiotic therapy is not recommended:

• In infants, bacterial enteritis is treated more aggressively with antibiotics due to the greater risk of developing severe sepsis. Seek expert advice for all infant enteritis cases
• If the results of microbiological testing are available before the symptoms of diarrhoea have resolved, adjust therapy accordingly
• The principal aim of treatment of acute infectious diarrhoea is to achieve and maintain adequate hydration. All patients with gastroenteritis should have their hydration status assessed so that appropriate rehydration can be given
• The usually self-limiting nature of acute infectious diarrhoea means that there is rarely a need for microbiological testing or antimicrobial therapy
• Faecal microbiological testing, when performed, rarely provides results during the acute stages of gastroenteritis. Perform testing in all patients who have features of severe disease (such as high fever, tachycardia, leucocytosis, abdominal tenderness or severe abdominal pain, high-volume diarrhoea with hypovolaemia, blood in the stool)

References:

See section on gastroenteritis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

What type of infection is suspected/confirmed?

• Appendicitis
• Cholecystitis
• Diverticulitis
• Pancreatitis
• Peritonitis
• Ascending cholangitis

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

Has an appendicectomy been performed?

• Yes
• No

Was the appendix ruptured or was there an appendiceal abscess?

• Yes
• No

If the patient has a mild penicillin allergy cover with:

Then, after surgery is performed, if a perforation or abscess was uncovered, consider step down to oral after initial improvement:

Code for ceftriaxone is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Following successful surgery IV therapy can be rapidly switched to oral therapy if patient is improving
• If the appendix was not perforated then antibiotic therapy can be discontinued immediately post appendicectomy
• For patients with a perforated appendix or an appendiceal abscess, the total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• When available the results of susceptibility testing should always guide treatment

References:

See section on appendicitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient has a mild penicillin allergy and the appendix was ruptured or an appendiceal abscess was uncovered treat with:

Then, after clinical condition improves, step down to oral:

Code for ceftriaxone is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Following successful surgery IV therapy can be rapidly switched to oral therapy if patient is improving. Please see the switch to oral criteria in the Therapeutic Guidelines (below)
• For patients with a perforated appendix or an appendiceal abscess, the total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• When available the results of susceptibility testing should always guide treatment

References:

See section on appendicitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the appendix was not perforated and no appendiceal abscess was uncovered:

No further antibiotic therapy should be necessary

References:

See section on appendicitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Has an appendicectomy been performed?

• Yes
• No

Was the appendix ruptured or was there an appendiceal abscess?

• Yes
• No

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

If the patient has a severe penicillin allergy cover with:

Code for IV clindamycin and gentamicin is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Following successful surgery IV therapy can be rapidly switched to oral therapy if patient is improving
• If the appendix was not perforated then antibiotic therapy can be discontinued immediately post appendicectomy
• If the appendix was perforated or an appendiceal abscess was uncovered then a total treatment duration (IV and oral) of 5 days is suggested
• When available the results of susceptibility testing should always guide treatment
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Paediatric Gentamicin Dosing (Age < 12 years)

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• For dosing in children with cystic fibrosis or those receiving chemotherapy, seek expert advice
• For children with impaired renal function (estimated glomerular filtration rate [eGFR] less than 50 mL/min/1.73 m²), give a single dose, then seek expert advice for subsequent dosing or selection of alternative drug. Use the modified Schwartz formula to estimate GFR
• Postmenstrual age is the time elapsed between the first day of the last menstrual period and birth (gestational age) plus the time elapsed after birth (postnatal age)
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on appendicitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient has a severe penicillin allergy and the appendix was ruptured or had an appendiceal abscess treat with:

Then, after clinical condition improves, step down to oral:

Code for IV clindamycin and gentamicin is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Please note clindamycin has excellent oral bioavailability (90% orally bioavailable), consider an early switch to oral therapy once patients clinical condition has improved
• Following successful surgery IV therapy can be rapidly switched to oral therapy if patient is improving. Please see the switch to oral criteria in the Therapeutic Guidelines (below)
• If the appendix was perforated or an appendiceal abscess was uncovered then a total treatment duration (IV and oral) of 5 days is suggested
• When available the results of susceptibility testing should always guide treatment
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Paediatric Gentamicin Dosing (Age < 12 years)

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• For dosing in children with cystic fibrosis or those receiving chemotherapy, seek expert advice
• For children with impaired renal function (estimated glomerular filtration rate [eGFR] less than 50 mL/min/1.73 m²), give a single dose, then seek expert advice for subsequent dosing or selection of alternative drug. Use the modified Schwartz formula to estimate GFR
• Postmenstrual age is the time elapsed between the first day of the last menstrual period and birth (gestational age) plus the time elapsed after birth (postnatal age)
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on appendicitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient has a contraindication to gentamicin and a severe penicillin allergy:

Please contact infectious diseases for advice

References:

See section on appendicitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Has an appendicectomy been performed?

• Yes
• No

Was the appendix ruptured or was there an appendiceal abscess?

• Yes
• No

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

If the patient tolerates penicillin cover with:

Then, after surgery is performed, if perforation or abscess was uncovered then consider step down to oral after initial improvement:

Code for gentamicin is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Following successful surgery IV therapy can be rapidly switched to oral therapy if patient is improving
• If the appendix was not perforated then antibiotic therapy can be discontinued immediately post appendicectomy
• If the appendix was perforated or an appendiceal abscess was uncovered then a total treatment duration (IV and oral) of 5 days is suggested
• When available the results of susceptibility testing should always guide treatment
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Paediatric Gentamicin Dosing (Age < 12 years)

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• For dosing in children with cystic fibrosis or those receiving chemotherapy, seek expert advice
• For children with impaired renal function (estimated glomerular filtration rate [eGFR] less than 50 mL/min/1.73 m²), give a single dose, then seek expert advice for subsequent dosing or selection of alternative drug. Use the modified Schwartz formula to estimate GFR
• Postmenstrual age is the time elapsed between the first day of the last menstrual period and birth (gestational age) plus the time elapsed after birth (postnatal age)
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on appendicitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient tolerates penicillin but not gentamicin and the appendix was ruptured or had an appendiceal abscess treat with:

Code for IV Amoxicillin+Clavulanate is: 5int

This code is valid for FIVE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Following successful surgery IV therapy can be rapidly switched to oral therapy if patient is improving. Please see the switch to oral criteria in the Therapeutic Guidelines (below)
• If the appendix was perforated or an appendiceal abscess was uncovered then a total treatment duration (IV and oral) of 5 days is suggested
• When available the results of susceptibility testing should always guide treatment

References:

See section on appendicitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient tolerates penicillin but not gentamicin cover with:

Code for IV Amoxicillin+Clavulanate is: 5int

This code is valid for FIVE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Following successful surgery IV therapy can be rapidly switched to oral therapy if patient is improving
• If the appendix was not perforated then antibiotic therapy can be discontinued immediately post appendicectomy
• If the appendix was perforated or an appendiceal abscess was uncovered then a total treatment duration (IV and oral) of 5 days is suggested
• When available the results of susceptibility testing should always guide treatment

References:

See section on appendicitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient tolerates penicillin and gentamicin give:

Code for gentamicin is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Following successful surgery IV therapy can be rapidly switched to oral therapy if patient is improving. Please see the switch to oral criteria in the Therapeutic Guidelines (below)
• If the appendix was perforated or an appendiceal abscess was uncovered then a total treatment duration (IV and oral) of 5 days is suggested
• When available the results of susceptibility testing should always guide treatment
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Paediatric Gentamicin Dosing (Age < 12 years)

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on appendicitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Are you treating calculous or acalculous cholecystitis?

• Acalculous cholecystitis
• Calculous cholecystitis

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

Has a cholecystectomy been performed?

• Yes
• No

If the patient has a mild penicillin allergy or does not tolerate gentamicin treat empirically with:

Once the patient's condition has improved, change to:

Code for ceftriaxone is: 2inb

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Antibiotic therapy should be ceased after uncomplicated cholecystectomy as the source of the infection has been removed
• If surgery is not performed the total treatment duration should not normally exceed 7 days (IV + oral)
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria
• Please see the switch to oral criteria in the Therapeutic Guidelines (below)

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Treatment post cholecystectomy should normally be ceased within 24 hours. If a further dose of surgical prophylaxis is deemed necessary give:

Code for ceftriaxone is: 1ina

This code is valid for ONE day only. Starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 24 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• If surgery is complicated in some way then please contact infectious diseases for approval of a longer course of IV antibiotics
• If surgery is not performed the total treatment duration should not normally exceed 7 days (IV + oral)
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Has a cholecystectomy been performed?

• Yes
• No

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

If the patient has a severe penicillin allergy cover with:

Code for gentamicin is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Antibiotic therapy should be ceased after uncomplicated cholecystectomy as the source of the infection has been removed
• If surgery is not performed the total treatment duration should not normally exceed 7 days (IV + oral)
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Following cholecystectomy antibiotic treatment should cease within 24 hours as the source of the infection has been removed. If a further dose of surgical prophylaxis is deemed necessary give:

Code for gentamicin is: 1ina

This code is valid for ONE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 24 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient has a contraindication to gentamicin and a severe penicillin allergy:

Please contact infectious diseases for advice

• Please note, following cholecystectomy antibiotic treatment should cease within 24 hours as the source of the infection has been removed

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Has a cholecystectomy been performed?

• Yes
• No

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

• Following successful cholecystectomy all antibiotic therapy should normally be ceased immediately after cholecystectomy as the source of infection has been removed. (If surgery was complicated please see antibiotic suggestions here)
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• When available, the results of susceptibility testing should always guide treatment

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient tolerates penicillin cover with:

Code for gentamicin is: 2int

This code is valid for ONE dose only. infectious diseases must be contacted if IV treatment is to continue past a single post-operative dose. NB/ gentamicin should only be given empirically for the first 48 hours, please check patient has not received any previous doses of gentamicin

See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

• Following successful cholecystectomy all antibiotic therapy should normally be ceased immediately after cholecystectomy as the source of infection has been removed. If surgery was complicated please contact infectious diseases for advice
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• If surgery is not performed the total treatment duration should not normally exceed 7 days (IV + oral)
• When available, the results of susceptibility testing should always guide treatment
• If IV therapy is required beyond 72 hours, cease the gentamicin-containing regimen and use ceftriaxone or piperacillin+tazobactam (see the therapeutic guidelines for details)

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Patients with severe sepsis have higher volumes of distribution and therefore require a higher mg/kg dose
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient tolerates penicillin but not gentamicin cover with:

Then, after clinical improvement:

Code for IV Amoxicillin+Clavulanate is: 2ina

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Antibiotic therapy should normally be stopped within 24 hours of cholecystectomy as the source of the infection has been removed, if surgery is complicated please contact infectious diseases for advice
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• If surgery is not performed the total treatment duration should not normally exceed 7 days (IV + oral)
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Has a cholecystectomy been performed?

• Yes
• No

Has a cholecystectomy been performed?

• Yes
• No

If the patient has a mild penicillin allergy or does not tolerate gentamicin treat empirically with:

Once the patient's condition has improved, change to:

Code for ceftriaxone is: 2inb

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• Antibiotic therapy should be ceased after uncomplicated cholecystectomy as the source of the infection has been removed
• If surgery not planned to be performed, please contact ID for long term antibiotic advice
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria
• Please see the switch to oral criteria in the Therapeutic Guidelines (below)

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Treatment post cholecystectomy should normally be ceased within 24 hours. If a further dose of surgical prophylaxis is deemed necessary give:

Code for ceftriaxone is: 1ina

This code is valid for ONE day only. Starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 24 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• If surgery is complicated in some way then please contact infectious diseases for approval of a longer course of IV antibiotics
• If surgery not planned to be performed, please contact ID for long term antibiotic advice
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Following cholecystectomy antibiotic treatment should cease within 24 hours as the source of the infection has been removed. If a further dose of surgical prophylaxis is deemed necessary give:

Code for gentamicin and clindamycin iv is: 1ina

This code is valid for ONE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 24 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Following cholecystectomy antibiotic treatment should cease within 24 hours as the source of the infection has been removed. If a further dose of surgical prophylaxis is deemed necessary give:

Code for gentamicin and IV clindamycin is: 2ina

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Has a cholecystectomy been performed?

• Yes
• No

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

If the patient has a severe penicillin allergy cover with:

Code for gentamicin and IV clindamycin is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• Antibiotic therapy should be ceased after uncomplicated cholecystectomy as the source of the infection has been removed
• If surgery not planned to be performed, please contact ID for long term antibiotic advice
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Following cholecystectomy antibiotic treatment should cease within 24 hours as the source of the infection has been removed. If a further dose of surgical prophylaxis is deemed necessary give:

Code for gentamicin and clindamycin iv is: 1ina

This code is valid for ONE days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 24 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria
• Metronidazole is not recommended for acute cholecystitis, and is only recommended in cases of ascending cholangitis with biliary obstruction present
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient has a contraindication to gentamicin and a severe penicillin allergy:

Please contact infectious diseases for advice

• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• Please note, following cholecystectomy antibiotic treatment should cease within 24 hours as the source of the infection has been removed

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Has a cholecystectomy been performed?

• Yes
• No

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Following cholecystectomy antibiotic treatment should cease within 24 hours as the source of the infection has been removed. If a further dose of surgical prophylaxis is deemed necessary give:

Ongoing antibiotic treatment should normally be continued for a maximum of 24 hours only:

Code for piperacillin is: 1ina

This code is valid for ONE day only. Starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 24 hours. NB/ gentamicin should only be given empirically for the first 48 hours, please check patient has not received any previous doses of gentamicin

• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• If surgery was complicated please contact infectious diseases for advice on treatment duration
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Following cholecystectomy antibiotic treatment should cease as the source of the infection has been removed. If the surgery was complicated give:

Code for gentamicin is: 1ina

This code is valid for ONE dose only. infectious diseases must be contacted if IV treatment is to continue past a single post-operative dose. NB/ gentamicin should only be given empirically for the first 48 hours, please check patient has not received any previous doses of gentamicin

• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• When available, the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient tolerates penicillin and gentamicin cover with:

Code for gentamicin is: 2int

This code is valid for ONE dose only. infectious diseases must be contacted if IV treatment is to continue past a single post-operative dose. NB/ gentamicin should only be given empirically for the first 48 hours, please check patient has not received any previous doses of gentamicin

• If surgery not planned to be performed, please contact ID for long term antibiotic advice
• When available, the results of susceptibility testing should always guide treatment
• If IV therapy is required beyond 72 hours, cease the gentamicin-containing regimen and use ceftriaxone or piperacillin+tazobactam (see the therapeutic guidelines for details)
• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Patients with severe sepsis have higher volumes of distribution and therefore require a higher mg/kg dose
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient tolerates penicillin but not gentamicin cover with:

Then, after clinical improvement:

Code for piperacillin is: 2inb

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Antibiotic therapy should normally be stopped within 24 hours of cholecystectomy as the source of the infection has been removed, if surgery is complicated please contact infectious diseases for advice
• If surgery not planned to be performed, please contact ID for long term antibiotic advice
• When available the results of susceptibility testing should always guide treatment
• Acute cholecystitis is usually caused by enteric Gram-negative bacilli (eg Escherichia coli and Klebsiella species) and, less commonly, Enterococcus faecalis. Infrequently, infection is caused by anaerobic bacteria
• The total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved

References:

See section on cholecystitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

How would you grade the diverticulitis? (See below)

• Mild
• Severe

• Patients with mild abdominal pain and tenderness who do not have significant systemic signs or symptoms should be considered to have mild diverticulitis
• Patients with peritonism, or those who have signs of diverticulitis and significant systemic signs or symptoms (eg fever, elevated white cell count), should be treated as severe or complicated diverticulitis

Does the patient have any of the following features?

• Immune compromise
• right sided diverticulitis
• failure to improve after 72 hours of conservative treatment (i.e. no antibiotic therapy)

• Yes
• No

• Antibiotics should only be considered for patients showing systemic symptoms such as fever or elevated white cell count, or patients who have failed to respond to conservative management (IV fluids and bowel rest)

For mild diverticulitis with no systemic involvement:

Antibiotic treatment may not be required.

Recent trials have suggested that antibiotic therapy may not be required for patients with mild abdominal pain and tenderness who do not have significant systemic signs or symptoms. If antibiotic therapy is deemed necessary then use the link below to continue to treatment:

• Antibiotic therapy is appropriate for patients with any of the following features:
  • immune compromise
  • right-sided diverticulitis
  • failure to improve after 72 hours of conservative treatment (ie no antibiotic therapy)

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

For diverticulitis in a patient with penicillin allergy use:

• Total antibiotic therapy should not normally exceed 5 days treatment
• Consider alternative diagnoses (eg irritable bowel syndrome). Diagnosis of diverticulitis made by clinical criteria alone has been shown to be incorrect in up to 33% of cases
• Antibiotics should only be considered in patients with signs of diverticulitis who have markers of systemic involvement (eg fever, elevated white cell count), or in patients who have failed to respond to conservative management

References:

See section on diverticulitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For diverticulitis in a patient tolerant of penicillin use as a single agent:

• Total antibiotic therapy should not normally exceed 5 days treatment
• Consider alternative diagnoses (eg irritable bowel syndrome). Diagnosis of diverticulitis made by clinical criteria alone has been shown to be incorrect in up to 33% of cases
• Antibiotics should only be considered in patients with signs of diverticulitis who have markers of systemic involvement (eg fever, elevated white cell count), or in patients who have failed to respond to conservative management

References:

See section on diverticulitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

References:

See section on diverticulitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

For diverticulitis in a patient with non-life threatening penicillin hypersensitivity use:

Code for ceftriaxone is: 2inb

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Consider alternative diagnoses (eg irritable bowel syndrome). Diagnosis of diverticulitis made by clinical criteria alone has been shown to be incorrect in up to 33% of cases
• Antibiotics should only be considered in patients with signs of diverticulitis who have markers of systemic involvement (eg fever, elevated white cell count), or in patients who have failed to respond to conservative management
• Consider a switch to oral once patient has been afebrile for 24 hours as with all abdominal infections
• For patients who have not undergone surgery, the total duration of therapy is 7 to 10 days (intravenous + oral)
• For patients who have undergone surgery, the total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved

References:

See section on diverticulitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For diverticulitis in a patient with life threatening penicillin hypersensitivity intolerant of gentamicin:

Please contact infectious diseases for advice

• Consider alternative diagnoses (eg irritable bowel syndrome). Diagnosis of diverticulitis made by clinical criteria alone has been shown to be incorrect in up to 33% of cases
• Antibiotics should only be considered in patients with signs of diverticulitis who have markers of systemic involvement (eg fever, elevated white cell count), or in patients who have failed to respond to conservative management
• Consider a switch to oral once patient has been afebrile for 24 hours as with all abdominal infections
• For patients who have not undergone surgery, the total duration of therapy is 7 to 10 days (intravenous + oral)
• For patients who have undergone surgery, the total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved

References:

See section on diverticulitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For diverticulitis in a patient with life threatening penicillin hypersensitivity use:

Code for IV clindamycin and gentamicin is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Consider a switch to oral once patient has been afebrile for 24 hours as with all abdominal infections
• If further intravenous therapy is required after 72 hours of empirical treatment with gentamicin, change therapy to ceftriaxone 2 g intravenously daily as for patients not tolerant of gentamicin
• Consider alternative diagnoses (eg irritable bowel syndrome). Diagnosis of diverticulitis made by clinical criteria alone has been shown to be incorrect in up to 33% of cases
• Antibiotics should only be considered in patients with signs of diverticulitis who have markers of systemic involvement (eg fever, elevated white cell count), or in patients who have failed to respond to conservative management
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Paediatric Gentamicin Dosing (Age < 12 years)

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• For dosing in children with cystic fibrosis or those receiving chemotherapy, seek expert advice
• For children with impaired renal function (estimated glomerular filtration rate [eGFR] less than 50 mL/min/1.73 m²), give a single dose, then seek expert advice for subsequent dosing or selection of alternative drug. Use the modified Schwartz formula to estimate GFR
• Postmenstrual age is the time elapsed between the first day of the last menstrual period and birth (gestational age) plus the time elapsed after birth (postnatal age)
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on diverticulitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For diverticulitis in a patient who can tolerate penicillin and gentamicin:

Code for gentamicin is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Consider a switch to oral once patient has been afebrile for 24 hours as with all abdominal infections
• For patients who have not undergone surgery, the total duration of therapy is 7 to 10 days (intravenous + oral)
• For patients who have undergone surgery, the total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• If further intravenous therapy is required after 72 hours of empirical treatment with gentamicin, change therapy to amoxicillin+clavulanate 1+0.2 g intravenously, 8-hourly as for patients not tolerant of gentamicin
• Consider alternative diagnoses (eg irritable bowel syndrome). Diagnosis of diverticulitis made by clinical criteria alone has been shown to be incorrect in up to 33% of cases
• Antibiotics should only be considered in patients with signs of diverticulitis who have markers of systemic involvement (eg fever, elevated white cell count), or in patients who have failed to respond to conservative management
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Paediatric Gentamicin Dosing (Age < 12 years)

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• For dosing in children with cystic fibrosis or those receiving chemotherapy, seek expert advice
• For children with impaired renal function (estimated glomerular filtration rate [eGFR] less than 50 mL/min/1.73 m²), give a single dose, then seek expert advice for subsequent dosing or selection of alternative drug. Use the modified Schwartz formula to estimate GFR
• Postmenstrual age is the time elapsed between the first day of the last menstrual period and birth (gestational age) plus the time elapsed after birth (postnatal age)
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

References:

See section on diverticulitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For diverticulitis in a patient tolerant of penicillin but intolerant of gentamicin use:

Code for piperacillin+tazobactam or IV amoxicillin+clavulanate is: 2inb

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Consider a switch to oral once patient has been afebrile for 24 hours as with all abdominal infections
• For patients who have not undergone surgery, the total duration of therapy is 7 to 10 days (intravenous + oral)
• For patients who have undergone surgery, the total duration of therapy is 5 days (intravenous + oral) after adequate surgical control of the source of infection has been achieved
• Consider alternative diagnoses (eg irritable bowel syndrome). Diagnosis of diverticulitis made by clinical criteria alone has been shown to be incorrect in up to 33% of cases
• Antibiotics should only be considered in patients with signs of diverticulitis who have markers of systemic involvement (eg fever, elevated white cell count), or in patients who have failed to respond to conservative management

References:

See section on diverticulitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

How severe is the pancreatitis?

• Mild or Moderate
• Severe (infected pancreatic necrosis/abscess)

• Refer all patients with severe pancreatitis to ICU
• Antibiotics are generally not indicated for acute pancreatitis
• The role of antibiotic therapy in the management of acute pancreatitis is limited to the treatment of infected pancreatic necrosis or pancreatic abscess
• The recognition and treatment of persisting obstruction and/or ascending cholangitis in patients with severe pancreatitis is important

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

For severe infected/necrotising pancreatitis in a patient with mild penicillin allergy:

Code for cefotaxime or ceftriaxone is: 2inp

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Patients with severe pancreatitis can intermittently appear septic during a prolonged hospitalisation. Before giving antibiotics, every effort should be made to perform image-guided percutaneous aspiration of any pancreatic collection, with Gram stain and cultures of the aspirate
• Treatment for infected pancreatic necrosis is a step-up approach using percutaneous drainage, minimally invasive surgery and, if necessary, open surgical debridement. In pancreatic abscess, prompt percutaneous or surgical drainage is important
• The recognition and treatment of persisting obstruction and/or ascending cholangitis in patients with severe pancreatitis is important
• Data to support the use of carbapenems in empirical treatment are lacking
• This is a guide for empirical therapy only. Modify therapy according to the results of cultures and susceptibility testing. Reserve carbapenems for infections caused by resistant pathogens
• Antibiotics are not indicated in the management of mild to moderate acute pancreatitis
• The optimal duration of therapy is uncertain. An initial course of 7 days is commonly used. The decision to prolong therapy should be based on careful review of the patient’s clinical status, and radiology and pathology results
• For cases that do not resolve within 7 to 10 days, consider secondary infection with Candida species or multidrug-resistant organisms such as vancomycin-resistant enterococci and carbapenem-resistant Enterobacteriaceae. Antimicrobial therapy should be directed by the results of culture and susceptibility testing of samples taken from a deep site—seek expert surgical, infectious diseases and clinical microbiology advice
• All patients with signs of infective necrotic pancreatitis should have an ICU assessment
• Acute pancreatitis may also be induced by drugs such as azathioprine and antiretroviral and chemotherapeutic drugs. However, when drug-induced pancreatitis is suspected, every drug that the patient is taking should be considered a possible cause

References:

See section on pancreatitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For infected/necrotising pancreatitis in a patient with major penicillin allergy:

Please contact infectious diseases for advice

• Patients with severe pancreatitis can intermittently appear septic during a prolonged hospitalisation. Before giving antibiotics, every effort should be made to perform image-guided percutaneous aspiration of any pancreatic collection, with Gram stain and cultures of the aspirate
• Treatment for infected pancreatic necrosis is a step-up approach using percutaneous drainage, minimally invasive surgery and, if necessary, open surgical debridement. In pancreatic abscess, prompt percutaneous or surgical drainage is important
• The recognition and treatment of persisting obstruction and/or ascending cholangitis in patients with severe pancreatitis is important
• Data to support the use of carbapenems in empirical treatment are lacking
• This is a guide for empirical therapy only. Modify therapy according to the results of cultures and susceptibility testing. Reserve carbapenems for infections caused by resistant pathogens
• Antibiotics are not indicated in the management of mild to moderate acute pancreatitis
• The optimal duration of therapy is uncertain. An initial course of 7 days is commonly used. The decision to prolong therapy should be based on careful review of the patient’s clinical status, and radiology and pathology results
• For cases that do not resolve within 7 to 10 days, consider secondary infection with Candida species or multidrug-resistant organisms such as vancomycin-resistant enterococci and carbapenem-resistant Enterobacteriaceae. Antimicrobial therapy should be directed by the results of culture and susceptibility testing of samples taken from a deep site—seek expert surgical, infectious diseases and clinical microbiology advice
• All patients with signs of infective necrotic pancreatitis should have an ICU assessment
• Acute pancreatitis may also be induced by drugs such as azathioprine and antiretroviral and chemotherapeutic drugs. However, when drug-induced pancreatitis is suspected, every drug that the patient is taking should be considered a possible cause

References:

See section on pancreatitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For infected necrotising pancreatitis or pancreatic abscess in a patient with no penicillin allergy:

Code for piperacillin+tazobactam is: 2inp

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• Patients with severe pancreatitis can intermittently appear septic during a prolonged hospitalisation. Before giving antibiotics, every effort should be made to perform image-guided percutaneous aspiration of any pancreatic collection, with Gram stain and cultures of the aspirate
• Treatment for infected pancreatic necrosis is a step-up approach using percutaneous drainage, minimally invasive surgery and, if necessary, open surgical debridement. In pancreatic abscess, prompt percutaneous or surgical drainage is important
• The recognition and treatment of persisting obstruction and/or ascending cholangitis in patients with severe pancreatitis is important
• Data to support the use of carbapenems in empirical treatment are lacking
• This is a guide for empirical therapy only. Modify therapy according to the results of cultures and susceptibility testing. Reserve carbapenems for infections caused by resistant pathogens
• Antibiotics are not indicated in the management of mild to moderate acute pancreatitis
• The optimal duration of therapy is uncertain. An initial course of 7 days is commonly used. The decision to prolong therapy should be based on careful review of the patient’s clinical status, and radiology and pathology results
• For cases that do not resolve within 7 to 10 days, consider secondary infection with Candida species or multidrug-resistant organisms such as vancomycin-resistant enterococci and carbapenem-resistant Enterobacteriaceae. Antimicrobial therapy should be directed by the results of culture and susceptibility testing of samples taken from a deep site—seek expert surgical, infectious diseases and clinical microbiology advice
• All patients with signs of infective necrotic pancreatitis should have an ICU assessment
• Acute pancreatitis may also be induced by drugs such as azathioprine and antiretroviral and chemotherapeutic drugs. However, when drug-induced pancreatitis is suspected, every drug that the patient is taking should be considered a possible cause

References:

See section on pancreatitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

For mild to moderate pancreatitis:

Antibiotics are not indicated for the management of mild or moderate pancreatitis

Antibiotics are only indicated if necrosis or systemic signs of infection are observed in severe cases of pancreatitis. These cases should be managed in the ICU/HDU. Gut rest, fluid administration and pain management are the mainstay of treatment for most cases of mild or moderate pancreatitis

• Refer all patients with severe pancreatitis to ICU
• Antibiotics are generally not indicated for acute pancreatitis
• The role of antibiotic therapy in the management of acute pancreatitis is limited to the treatment of infected pancreatic necrosis or pancreatic abscess
• The recognition and treatment of persisting obstruction and/or ascending cholangitis in patients with severe pancreatitis is important

References:

See section on pancreatitis - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

What is the cause of the peritonitis?

• Perforated viscus
• Spontaneous (SBP)
• Peritoneal dialysis

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

Does the patient have a penicillin allergy? (See below for details on penicillin allergy severity)

• No penicillin allergy
• Non-severe immediate or delayed penicillin hypersensitivity
• Severe immediate or delayed penicillin hypersensitivity

History of penicillin allergy or adverse reaction

No penicillin allergy

• This includes non-severe reactions such as nausea and limited diarrhoea
• Such reactions are frequently not replicable or generalizable to the whole class. It is safe to prescribe penicillin class antibiotics (with the patient’s knowledge), and if required, use strategies for symptom control such as metoclopramide

Non-severe immediate or delayed penicillin hypersensitivity

• This includes non-severe reactions such as isolated rash
• There is only a 2-3% chance of cephalosporin allergy in a patient with a previous IgE mediated allergy to penicillin, and probably even less for other types of allergies. In most cases it is safe to administer a cephalosporin to a patient who has had a non-life threatening reaction to penicillin

Severe immediate or delayed penicillin hypersensitivity

• This includes anaphylaxis (see below) BUT DOES NOT INCLUDE other life-threatening reactions such as Stevens-Johnson Syndrome (SJS), Toxic epidermal necrolysis (TEN), Drug reaction with eosinophilia and systemic symptoms (DRESS) or interstitial nephritis. If your patient has a history of these, contact infectious diseases for advice

Penicillin anaphylaxis is highly likely if any ONE of the following is fulfilled:

OR

OR

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

Is gentamicin contraindicated in this patient? (See below for contraindications)

• Gentamicin not contraindicated
• Gentamicin contraindicated

Aminoglycoside Contraindications and Precautions

• A single dose can be used in patients with:
  • Chronic renal impairment (creatinine clearance less than 40 mL/min) or rapidly deteriorating renal function
  • Advanced age (eg 80 years or older), depending on calculated renal function
• If you are unsure whether gentamicin is appropriate for this patient please consult infectious diseases

If the patient has a mild penicillin allergy, until the return of susceptibility results cover with:

Then, after clinical improvement is observed (patient is afebrile for at least 24 hours) switch to oral:

Code for ceftriaxone is: 2inb

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• As with all intra-abdominal infections, IV therapy can be rapidly switched to oral therapy if patient is improving (generally within the first 48 hours after intiating IV therapy)
• Empirical antifungal therapy is not normally required, however consider antifungal therapy if yeasts are uncovered from deep surgical site samples
• When available, the results of susceptibility testing should always guide treatment
• Peritonitis is usually a polymicrobial infection with aerobic and anaerobic bowel flora. Peritonitis from a perforated viscus normally requires surgery

References:

See section on peritonitis due to perforated viscus - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient has a severe penicillin allergy cover with:

Then, after clinical improvement is observed (patient is afebrile for at least 24 hours) switch to oral:

Code for IV clindamycin is: 2int

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

Code for gentamicin is: 2inb

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• As with all intra-abdominal infections, IV therapy can be rapidly switched to oral therapy if patient is improving (generally within the first 48 hours after intiating IV therapy)
• Empirical antifungal therapy is not normally required, however consider antifungal therapy if yeasts are uncovered from deep surgical site samples
• When available, the results of susceptibility testing should always guide treatment
• Peritonitis is usually a polymicrobial infection with aerobic and anaerobic bowel flora. Peritonitis from a perforated viscus normally requires surgery
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

Initial Paediatric Gentamicin Dosing (Age < 12 years)

• If actual body weight is more than 20% over the ideal body weight, use adjusted body weight to calculate the dose. For morbidly obese patients, seek expert advice
• Critically ill patients with severe sepsis have higher volumes of distribution. In these patients a dose of up to 7mg/kg may be appropriate (depending on renal function). See the Therapeutic Guidelines for more detail
• For dosing in children with cystic fibrosis or those receiving chemotherapy, seek expert advice
• For children with impaired renal function (estimated glomerular filtration rate [eGFR] less than 50 mL/min/1.73 m²), give a single dose, then seek expert advice for subsequent dosing or selection of alternative drug. Use the modified Schwartz formula to estimate GFR
• Postmenstrual age is the time elapsed between the first day of the last menstrual period and birth (gestational age) plus the time elapsed after birth (postnatal age)
• Use the Cockcroft gault calculator to calculate renal function for adults if using the nomogram, or use the adult aminoglycoside dose calculator

If the patient has a severe penicillin allergy and can not tolerate gentamicin:

Please contact infectious diseases there are limited treatment options if a patient can not tolerate penicillin or gentamicin

• As with all intra-abdominal infections, IV therapy can be rapidly switched to oral therapy if patient is improving (generally within the first 48 hours after intiating IV therapy)
• Empirical antifungal therapy is not normally required, however consider antifungal therapy if yeasts are uncovered from deep surgical site samples
• When available, the results of susceptibility testing should always guide treatment
• Peritonitis is usually a polymicrobial infection with aerobic and anaerobic bowel flora. Peritonitis from a perforated viscus normally requires surgery

References:

See section on peritonitis due to perforated viscus - Antibiotic Expert Groups. Therapeutic guidelines: antibiotic. Version 15. Melbourne: Therapeutic Guidelines Limited; 2019.

If the patient tolerates penicillin cover with:

Code for gentamicin is: 2inb

This code is valid for TWO days only, starting from the first day of treatment for this condition. Infectious diseases must be contacted if IV treatment is to continue past 48 hours. Please annotate this code on the medication chart and document when infectious diseases are to be contacted in the patient notes.

• If further IV treatment is required after 72 hours of empirical treatment with gentamicin, change patient to piperacillin and tazobactam 4/0.5g (child: 100+12.5 mg/kg up to 4+0.5 g) 8-hourly until clinically improved as for patients not tolerant of gentamicin
• As with all intra-abdominal infections, IV therapy can be rapidly switched to oral therapy if patient is improving (generally within the first 48 hours after intiating IV therapy)
• Empirical antifungal therapy is not normally required, however consider antifungal therapy if yeasts are uncovered from deep surgical site samples
• When available, the results of susceptibility testing should always guide treatment
• Peritonitis is usually a polymicrobial infection with aerobic and anaerobic bowel flora. Peritonitis from a perforated viscus normally requires surgery
• See the Therapeutic Guidelines - Clinical Monitoring for aminoglycoside toxicity section for more information on monitoring for possible aminoglycoside toxicity

Initial Gentamicin/Tobramycin Dosing (age > 12 years)

Initial Paediatric Gentamicin Dosing (Age < 12 years)