Meropenem Dosage Adjustments in Renal Impairment
For patients with renal impairment, meropenem dosage should be adjusted based on creatinine clearance, with frequency reduction rather than dose reduction being the primary approach. 1
Adult Dosing Recommendations
Based on Creatinine Clearance:
- CrCl >50 mL/min: Standard dose (500 mg for cSSSI or 1 gram for intra-abdominal infections) every 8 hours 1
- CrCl 26-50 mL/min: Standard dose every 12 hours 1
- CrCl 10-25 mL/min: Half the standard dose every 12 hours 1
- CrCl <10 mL/min: Half the standard dose every 24 hours 1
Special Considerations:
- For infections caused by Pseudomonas aeruginosa, a higher dose of 1 gram every 8 hours is recommended in patients with normal renal function, with appropriate adjustments for renal impairment 1
- Administration should be via intravenous infusion over 15-30 minutes or intravenous bolus injection over 3-5 minutes 1
Patients on Renal Replacement Therapy
- Hemodialysis: Meropenem is readily dialyzable with approximately 50% removed during hemodialysis sessions 2
- Hemodialysis shortens the elimination half-life from approximately 7 hours to 2.9 hours in end-stage renal disease patients 3
- Dosing after each hemodialysis session is recommended for patients receiving intermittent hemodialysis 3
- Continuous Renal Replacement Therapy (CRRT): Dosing may need to be increased by up to 100% compared to standard recommendations for anuric patients, as CRRT contributes significantly to meropenem elimination 4
Pharmacokinetic Considerations
- Meropenem's half-life increases from approximately 1 hour in healthy individuals to up to 13.7 hours in patients with end-stage renal disease 2
- The total clearance of meropenem correlates linearly with glomerular filtration rate 5
- In patients with normal renal function, approximately 80% of meropenem is eliminated via renal clearance, with the remaining 20% via non-renal routes 5
- As renal function declines, the proportion of non-renal clearance increases, accounting for about 50% of total elimination in patients with severe renal impairment 5
Safety Profile
- Meropenem has an excellent safety profile even in elderly and renally impaired patients 6
- The incidence of seizures is rare (0.1%) even in patients with renal impairment 6
- The pattern and frequency of adverse events in elderly and/or renally impaired patients are similar to those in younger patients with normal renal function 6
Clinical Pitfalls to Avoid
- Underdosing is a common risk when treating patients on renal replacement therapy due to varying recommendations in literature 2
- Given meropenem's excellent tolerability profile, it's generally better to err on the side of adequate dosing rather than underdosing, especially for serious infections 2
- Monitoring for neurological symptoms is important in patients with renal dysfunction, although meropenem has a lower risk of neurotoxicity compared to some other beta-lactams 7
- Regular assessment of renal function is necessary during treatment to adjust dosing as needed 6