Meropenem Dosing in Hemodialysis Patients
For adult patients on intermittent hemodialysis, administer meropenem 500 mg intravenously every 24 hours, given after each dialysis session on dialysis days.
Pharmacokinetic Rationale
- Meropenem is predominantly excreted unchanged in the urine, requiring significant dose adjustment in renal failure 1
- The elimination half-life extends from approximately 1 hour in healthy individuals to 7-13.7 hours in anuric patients with end-stage renal disease 1, 2
- Approximately 50% of meropenem is removed during a standard intermittent hemodialysis session 1
- Hemodialysis shortens the elimination half-life from 7.0 hours to 2.9 hours during the dialysis procedure 2
Specific Dosing Algorithm
Standard regimen:
- 500 mg IV every 24 hours for patients with creatinine clearance <30 mL/min or on hemodialysis 2
- Administer the dose immediately after hemodialysis on dialysis days to prevent premature drug removal 2
- On non-dialysis days, maintain the 24-hour dosing interval 2
For severe infections or resistant organisms:
- Consider 1 g IV every 12 hours if treating Pseudomonas aeruginosa or other organisms with higher MIC requirements 3
- This higher dose maintains serum concentrations above 4 mg/L (MIC90 for P. aeruginosa) for 67% of the dosing interval 3
Critical Pitfalls to Avoid
Risk of underdosing:
- The standard 500 mg daily dose may be insufficient for critically ill patients or those with severe infections requiring higher drug concentrations 4
- Extended daily dialysis removes 18% of meropenem per session, potentially leading to subtherapeutic levels with standard dosing 4
Risk of neurotoxicity:
- The recommended 500 mg daily dose may still cause seizures in some hemodialysis patients, particularly those with lower body mass index 5
- Monitor closely for central nervous system toxicity including confusion, myoclonus, and seizures, especially after multiple doses 5
- If seizures occur, discontinue meropenem immediately 5
Monitoring Recommendations
- Clinical monitoring: Assess for signs of CNS toxicity (confusion, tremors, seizures) after each dose, particularly after the 5th-7th dose 5
- Therapeutic drug monitoring: Consider measuring serum concentrations when available to ensure adequate levels without excessive accumulation 1, 4
- Timing verification: Confirm doses are administered post-dialysis to maximize drug retention 2
Special Considerations
- For patients on continuous renal replacement therapy (CVVHF or CVVHDF), dosing differs significantly: use 1 g IV every 12 hours due to continuous drug removal 3
- The fraction cleared by extracorporeal routes during continuous therapy is approximately 48%, requiring higher and more frequent dosing than intermittent hemodialysis 3
- Adjust dosing based on infection severity, pathogen MIC, and clinical response rather than using a one-size-fits-all approach 4