Meropenem Dosing in Patients on Dialysis
For patients on hemodialysis, meropenem should be dosed at 500 mg every 24 hours, with an additional dose administered after each dialysis session. 1
Pharmacokinetics in Renal Failure
Meropenem is predominantly excreted unchanged in the urine, making dosage adjustments necessary for patients with renal impairment, particularly those on dialysis. The drug's half-life increases significantly from approximately 1 hour in patients with normal renal function to up to 13.7 hours in patients with end-stage renal disease 2.
Key pharmacokinetic changes in dialysis patients:
- Terminal half-life increases to approximately 7 hours in patients with end-stage renal disease 3
- Hemodialysis effectively removes meropenem, shortening the half-life from 7 hours to 2.9 hours during dialysis 3
- Dialysis clearance of meropenem is approximately 79-81 ml/min 4
Dosing Recommendations
According to the FDA-approved drug label, the following dosing adjustments are recommended for patients with renal impairment 1:
| Creatinine Clearance (mL/min) | Dose | Dosing Interval |
|---|---|---|
| Greater than 50 | Recommended dose (500 mg cSSSI and 1 gram Intra-abdominal) | Every 8 hours |
| 26 to 50 | Recommended dose | Every 12 hours |
| 10 to 25 | One-half recommended dose | Every 12 hours |
| Less than 10 | One-half recommended dose | Every 24 hours |
While the FDA label states that "there is inadequate information regarding the use of meropenem for injection in patients on hemodialysis or peritoneal dialysis" 1, multiple pharmacokinetic studies provide clear guidance.
Hemodialysis-Specific Recommendations
For patients on intermittent hemodialysis:
- Administer 500 mg every 24 hours 3
- Give an additional dose after each hemodialysis session to compensate for drug removal during dialysis 3, 5
- Timing is important: administer the dose after dialysis to prevent premature removal of the drug 2
Continuous Renal Replacement Therapy (CRRT)
For patients on CRRT, dosing requirements may differ:
- Approximately 25-50% of meropenem is eliminated by continuous venovenous hemofiltration (CVVHF) 2
- 13-53% is eliminated by continuous venovenous hemodiafiltration (CVVHDF) 2
- For patients on CRRT with preserved residual diuresis, 500 mg every 8 hours as an extended infusion over 3 hours may be appropriate 6
- For oligoanuric patients on CRRT, 500 mg every 8 hours as a bolus over 30 minutes is generally sufficient 6
Important Clinical Considerations
Timing of administration: Always administer meropenem after hemodialysis to prevent premature removal of the drug 2, 3
Residual renal function: Consider residual diuresis when determining dosing regimens, as it significantly impacts meropenem clearance 6
Target organism MIC: For bacteria with higher MICs (2-4 mg/L), more aggressive dosing may be required 6
Monitoring: Regular clinical assessment for therapeutic response and potential adverse effects is essential
Potential for underdosing: Given the excellent tolerability profile of meropenem, clinicians should be more concerned about underdosing than overdosing, particularly when treating serious infections 2
By following these recommendations, clinicians can optimize meropenem therapy in dialysis patients to achieve therapeutic concentrations while avoiding unnecessary drug exposure.