From the Research
Meropenem dosing in neonates with renal failure should be carefully adjusted based on gestational age, postnatal age, and degree of renal impairment, with a recommended approach of maintaining the standard dose but extending the dosing interval, as supported by the most recent study 1.
Key Considerations
- Standard neonatal meropenem dosing is 20-40 mg/kg/dose, with the higher end used for meningitis.
- In renal failure, dosing intervals should be extended from every 8-12 hours to every 12-24 hours depending on the severity of renal impairment.
- For severe renal failure (creatinine clearance <10 ml/min/1.73m²), consider extending to every 24 hours.
- Therapeutic drug monitoring is highly recommended when available to guide dosing, as meropenem clearance can be difficult to predict in neonates with renal failure and those undergoing continuous renal replacement therapy 1.
Rationale
Meropenem is primarily eliminated by the kidneys, with approximately 70% excreted unchanged in urine, making dose adjustment necessary in renal impairment to prevent drug accumulation and toxicity.
Monitoring and Adjustments
Clinicians should regularly reassess renal function, as it can change rapidly in neonates, particularly premature infants whose renal function is still developing. Signs of meropenem toxicity, such as seizures and thrombocytopenia, should be monitored closely in these vulnerable patients.
Additional Guidance
A study on critically ill children receiving continuous renal replacement therapy found that dosing of 20 mg/kg every 8 hours over 4 hours or 40 mg/kg every 8 hours over 2 hours achieved the pharmacokinetic/pharmacodynamic target in at least 90% of simulated patients 2. However, the most recent study 1 highlights the importance of individualized dosing and therapeutic drug monitoring in neonates with renal failure, making it the primary guide for dosing recommendations.