Meropenem Dosage Per Kilogram Body Weight
The standard dosage of meropenem for adults is 1 gram every 8 hours (not weight-based), while pediatric patients should receive 10-40 mg/kg every 8 hours depending on infection type, with a maximum of 2 grams per dose. 1, 2
Adult Dosing
- Standard adult dosing is not weight-based but fixed:
- 500 mg every 8 hours for skin and skin structure infections
- 1 gram every 8 hours for intra-abdominal infections
- 1 gram every 8 hours for infections caused by P. aeruginosa
- 2 grams every 8 hours for severe infections (maximum dose)
Pediatric Dosing
For pediatric patients, dosing is weight-based:
Children 3 Months and Older:
- Complicated skin and skin structure infections: 10 mg/kg every 8 hours (max 500 mg/dose)
- Complicated intra-abdominal infections: 20 mg/kg every 8 hours (max 1 gram/dose)
- Meningitis: 40 mg/kg every 8 hours (max 2 grams/dose)
- For P. aeruginosa infections: 20 mg/kg every 8 hours
Children Less Than 3 Months:
Based on gestational age (GA) and postnatal age (PNA):
- Infants <32 weeks GA and PNA <2 weeks: 20 mg/kg every 12 hours
- Infants <32 weeks GA and PNA ≥2 weeks: 20 mg/kg every 8 hours
- Infants ≥32 weeks GA and PNA <2 weeks: 20 mg/kg every 8 hours
- Infants ≥32 weeks GA and PNA ≥2 weeks: 30 mg/kg every 8 hours
Dosage Adjustments for Renal Impairment
Dosage should be reduced in patients with creatinine clearance ≤50 mL/min:
| Creatinine Clearance (mL/min) | Dose | Dosing Interval |
|---|---|---|
| >50 | Standard dose | Every 8 hours |
| 26-50 | Standard dose | Every 12 hours |
| 10-25 | Half standard dose | Every 12 hours |
| <10 | Half standard dose | Every 24 hours |
Administration Methods
- Standard administration: Intravenous infusion over 15-30 minutes
- Extended infusion: 3-4 hours for severe infections or when treating bacteria with high MICs
- Bolus injection: Can be administered over 3-5 minutes (for doses up to 1 gram)
Special Considerations
- For critically ill patients with septic shock, the recommended dose is 1 gram every 8 hours 3
- For patients on continuous renal replacement therapy, dosing should be adjusted based on residual diuresis 4
- For pediatric patients receiving extracorporeal life support, higher doses may be required to achieve therapeutic levels 5
Common Pitfalls to Avoid
- Underdosing in severe infections, especially when treating resistant organisms
- Failure to adjust dosing in renal impairment
- Not considering extended infusion for severe infections or resistant organisms
- Not accounting for increased clearance in patients with augmented renal clearance
Meropenem is a valuable antibiotic for serious infections, and appropriate dosing based on patient age, weight (for pediatrics), renal function, and infection severity is crucial for optimal outcomes.