| Age | Initial dose |
Dosing frequency |
Maximum number of empirical doses |
|
|---|---|---|---|---|
| Neonates <30 weeks postmenstrual age |
postnatal age 0 to 7 days |
5 mg/kg | 48-hourly | 2 doses (at 0 and 48 hours) |
| postnatal age 8 to 28 days |
4 mg/kg | 36-hourly | 2 doses (at 0 and 36 hours) |
|
| postnatal age 29 days or older |
4 mg/kg | 24-hourly | 3 doses (at 0, 24 and 48 hours) |
|
| neonates 30 to 34 weeks postmenstrual age |
postnatal age 0 to 7 days |
4.5 mg/kg | 36-hourly | 2 doses (at 0 and 36 hours) |
| postnatal age 8 days and older |
4 mg/kg | 24-hourly | 3 doses (at 0, 24 and 48 hours) |
|
| neonates 35 weeks postmenstrual age or older |
4 mg/kg | 24-hourly | 3 doses (at 0, 24 and 48 hours) |
|
| infants and children | 7.5 mg/kg | 24-hourly | 3 doses (at 0, 24 and 48 hours) |
|
| Creatinine clearance (mL/min) |
Initial dose |
Dosing frequency |
Maximum number of empirical doses |
|---|---|---|---|
| More than 60 mL/min |
4 to 5 mg/kg | 24-hourly | 3 doses (at 0, 24 and 48 hours) |
| 40 to 60 mL/min | 4 to 5 mg/kg | 36-hourly | 2 doses (at 0 and 36 hours) |
| less than 40 mL/min |
4mg/kg | Single dose, then seek expert advice | |
| Age | Starting Dose (use actual body weight) |
Dosing frequency |
Timing of first trough concentration |
|
|---|---|---|---|---|
| Neonates < 30 weeks postmenstrual age (NB1) |
postnatal age 0 to 14 days |
15 mg/kg | 18-hourly | Before the second dose |
| postnatal age 14 days or older |
15 mg/kg | 12-hourly | Before the third dose | |
| Neonates 30 to 36 weeks postmenstrual age (NB1) |
postnatal age 0 to 14 days |
15 mg/kg | 12-hourly | Before the third dose |
| postnatal age 15 days or older |
15 mg/kg | 8-hourly | Before the fourth dose | |
| Neonates 37 to 44 weeks postmenstrual age (NB1) |
postnatal age 0 to 7 days |
15 mg/kg | 12-hourly | Before the third dose |
| postnatal age 8 days or older |
15 mg/kg | 8-hourly | Before the fourth dose | |
| Neonates 45 weeks postmenstrual age or older (NB1) | 15 mg/kg | 6-hourly | Before the fifth dose | |
| Infants and children (NB2) | 15 mg/kg up to 750 mg | 6-hourly | Before the fifth dose | |
| Actual body weight (kg) |
CrClr < 20 mL/min |
CrClr 20-40 mL/min |
CrClr 40-60 mL/min |
CrClr > 60 mL/min |
Administer over(1) |
| < 40 | 15 to 20 mg/kg 48 to 72 hly |
15 to 20 mg/kg 24-hly |
15 to 20 mg/kg daily, in 1 or 2 divided doses |
15 to 20 mg/kg 12-hly |
--- |
| 40-49 | 750 mg 48 to 72 hly |
750 mg 24 hly |
750 mg daily, in 1 or 2 divided doses |
750 mg 12 hly |
1 hr 15 min |
| 50-64 | 1000 mg 48 hly |
1000 mg 24 hly |
1000 mg daily, in 1 or 2 divided doses |
1000 mg 12 hly |
1 hr 40 min |
| 65-78 | 1250 mg 48 hly |
1250 mg 24 hly |
1250 mg daily, in 1 or 2 divided doses |
1250 mg 12 hly |
2 hrs 5 min |
| 79-92 | 1500 mg 48 hly |
1500 mg 24 hly |
1500 mg daily, in 1 or 2 divided doses |
1500 mg 12 hly |
2 hrs 30 min |
| 93-107 | 1750 mg 48 hly |
1750 mg 24 hly |
1750 mg daily, in 1 or 2 divided doses |
1750 mg 12 hly |
3 hrs |
| > 108 | 2000 mg 48 hly |
2000 mg 24 hly |
2000 mg daily, in 1 or 2 divided doses |
2000 mg 12 hly |
3 hrs 30 min |
| Timing of 1st trough level(2) |
48 hrs after the 1st dose(3) |
Before the 3rd dose |
48 hrs after the 1st dose(3) |
Before the 4th dose |
--- |
| Antibiotic | Average Half-Life (in Normal Adult Patient) | Elapsed Time before Second Dose Required |
|---|---|---|
| Second dose required if surgery delayed/prolonged > 3 hours | ||
| Benzyl Penicillin | 0.3 – 0.8 hours | 2 hours |
| Flucloxacillin | 0.75 – 1.5 hours | 3 hours |
| Cefazolin | 1.8 hours | 3 hours |
| Second dose may not be required if surgery delayed/prolonged > 3 hours ☸ | ||
| Piperacillin/tazobactam | 1 – 6 hours | 2 – 12 hours ☸ |
| Clindamycin | 1.5 – 5 hours | 3 to 4 hours ☸ |
| Ciprofloxacin | 4 hours | 8 hours ☸ |
| Vancomycin | 4 – 6 hours | 8 hours ☸ |
| Metronidazole | 6 - 7 hours | 12 hours ☸ |
| Teicoplanin | 90 – 157 hours | Not required |
| Gentamicin | 2 hours - NB/ despite having a short half-life a second dose of gentamicin should never be given within 24 hours due to the potential for nephrotoxicity and ototoxicity with this agent If the operation is expected to be extended then a higher initial dose (up to 5mg/Kg) gentamicin should be given . | No second dose to be given |
| Oral Alternatives to Intravenous Medicines | |||
|---|---|---|---|
| Intravenous | Oral | ||
| Antimicrobial Agent and Usual Adult Dose | Daily Cost | Antimicrobial Agent and Usual Adult Dose | Daily Cost |
| Amoxicillin 1-2g Q6H | $4.79 - $9.58 | Amoxicillin 500mg-1g Q8H | 16c-49c |
| Azithromycin 500mg Daily | $5.67 | Azithromycin 500mg Daily | $2.69 |
| Roxithromycin 300mg Daily | 57c | ||
| Benzyl penicillin 1.2g Q6H | $24.34 | Amoxicillin 500mg-1 gm Q8H | 16c-49c |
| Ceftriaxone 1-2g Daily | 88c | For COAD exacerbation - Amoxicillin 500mg oral Q8H (∂) | 16c |
| For Community Acquired Pneumonia - Amoxicillin 1g Q8H (∂) | 49c | ||
| For Hospital Acquired or Aspiration Pneumonia, Abdominal Sepsis and UTI - Amoxicillin/Clavulanic Acid 875mg/125mg Q12H (∂)(∅) |
40c | ||
| Cefazolin 1-2g Q8H | $4.35 | Cefalexin 500mg Q6H | 30c |
| Ciprofloxacin 200-400mg Q12H | $15.92 | Ciprofloxacin 500-750mg Q12H | 23c – 98c |
| Flucloxacillin 1g Q6H | $5.41 - $10.82 | Flucloxacillin 500mg Q6H | $1.20 |
| Fluconazole 200-400mg Daily | $3.45 - $6.90 | Fluconazole 200mg-400mg Daily (∑) | 65c - $1.30 |
| Clindamycin 600-900mg Q8H | $81 - $162 | Clindamycin 300-600mg oral Q8H (∑) | $1.99 - $3.98 |
| Metronidazole 500mg Q12H | $3.69 | Metronidazole 400mg Q8H – Q12H (∑) | 41c |
| Piperacillin / Tazobactam 4.5g Q8H | $25.69 | Amoxicillin/Clavulanic acid 875mg/125mg oral Q12H (∅) | 40c |
| ∂ | Ensure patient does not have penicillin allergy before changing | ||
| ∅ | No direct oral alternative. Check microbiology and site of infection to guide choice of agent | ||
| ∑ | Agents with excellent oral bioavailability (90% or higher) | ||
