Meropenem Dosing in Pediatric Patients
For pediatric patients 3 months and older with severe infections, administer meropenem at 10-20 mg/kg every 8 hours for most infections, 40 mg/kg every 8 hours (maximum 2 grams) for meningitis, with doses given as 15-30 minute infusions or 3-5 minute bolus injections. 1
Standard Dosing by Indication (≥3 Months of Age)
Complicated Skin and Skin Structure Infections
- 10 mg/kg every 8 hours (maximum 500 mg per dose) 1
- For Pseudomonas aeruginosa infections: increase to 20 mg/kg every 8 hours (maximum 1 gram per dose) 1
Complicated Intra-abdominal Infections
- 20 mg/kg every 8 hours (maximum 1 gram per dose) 1
Bacterial Meningitis
- 40 mg/kg every 8 hours (maximum 2 grams per dose) 1
- This higher dose is critical for adequate CSF penetration, as clinical cure in meningitis patients correlates with achieving at least 75.3% time above MIC in CSF 2
- The 40 mg/kg dose is necessary for penicillin-resistant Streptococcus pneumoniae and Pseudomonas aeruginosa meningitis 2
Multidrug-Resistant Infections
- For multidrug-resistant tuberculosis: 20-40 mg/kg per dose three times daily, typically combined with clavulanate 3
- For carbapenem-resistant Enterobacterales: follow standard dosing recommendations but anticipate need for combination therapy 3
Neonatal Dosing (<3 Months of Age)
Dosing is based on both gestational age (GA) and postnatal age (PNA): 1
- Infants <32 weeks GA and PNA <2 weeks: 20 mg/kg every 12 hours 1
- Infants <32 weeks GA and PNA ≥2 weeks: 20 mg/kg every 8 hours 1
- Infants ≥32 weeks GA and PNA <2 weeks: 20 mg/kg every 8 hours 1
- Infants ≥32 weeks GA and PNA ≥2 weeks: 30 mg/kg every 8 hours 1
All neonatal doses should be given as 30-minute infusions 1. This regimen has demonstrated safety and efficacy in preterm neonates with severe infections, including those caused by resistant organisms 4
Administration Methods
Standard Infusion
Bolus Administration
- 3-5 minute bolus injection is acceptable for doses up to 1 gram 1
- Limited safety data exist for 40 mg/kg (2 gram) bolus doses 1
Extended Infusion (Critical Illness)
- 3-4 hour infusion significantly improves pharmacodynamic target attainment in critically ill children 5, 6
- For organisms with MIC of 1 mg/L, a 3-hour infusion of 20 mg/kg achieves nearly 100% probability of target attainment versus only 67.8% with bolus dosing 5
- Consider continuous infusion at 110 mg/kg/day for critically ill patients with pathogens having MICs of 4-8 mg/L 6
Critical Dosing Considerations
Weight-Based Adjustments
- Patients >50 kg: use adult dosing (500 mg every 8 hours for skin infections, 1 gram every 8 hours for intra-abdominal infections, 2 grams every 8 hours for meningitis) 1
Renal Impairment
- No established pediatric dosing guidelines exist for renal impairment 1
- Approximately 55% of meropenem is renally excreted unchanged 7
- In multidrug-resistant tuberculosis with renal dysfunction, reduce dosing frequency 3
Pharmacokinetic Principles
- Meropenem exhibits a half-life of approximately 1.13 hours in children 7
- Volume of distribution is 0.43 L/kg 7
- No significant age-dependent effects on pharmacokinetics occur in children 2 months to 12 years 7
- Weight and creatinine clearance significantly correlate with meropenem clearance in critically ill children 6
Common Pitfalls and How to Avoid Them
Inadequate Dosing for Resistant Organisms
- Standard 20 mg/kg bolus dosing every 8 hours is insufficient for organisms with MIC ≥1 mg/L 5
- Solution: Use extended infusions (3-4 hours) or increase dose to 40 mg/kg for serious infections 5, 6
Meningitis Underdosing
- Using 20 mg/kg instead of 40 mg/kg for meningitis results in inadequate CSF concentrations 2
- Solution: Always use 40 mg/kg every 8 hours for confirmed or suspected bacterial meningitis 1, 2
Critical Illness Considerations
- Standard dosing regimens often fail to achieve pharmacodynamic targets in critically ill children 6
- Solution: Consider 40 mg/kg every 8 hours as 4-hour infusions or continuous infusion at 110 mg/kg/day 6