Meropenem Dosing Recommendations
Adults with Normal Renal Function
For adults with normal renal function, administer meropenem 1 gram IV every 8 hours by extended infusion over 3 hours for severe infections, or standard infusion over 15-30 minutes for less severe infections. 1
Standard Dosing by Indication:
- Complicated intra-abdominal infections: 1 gram IV every 8 hours 1, 2
- Complicated skin and skin structure infections: 500 mg IV every 8 hours (or 1 gram every 8 hours if Pseudomonas aeruginosa is suspected) 2
- Hospital-acquired or ventilator-associated pneumonia: 1 gram IV every 8 hours 1
- Bloodstream infections with carbapenem-resistant organisms: 1 gram IV every 8 hours by extended 3-hour infusion 1
Administration Methods:
- Standard infusion: 15-30 minutes for routine infections 2
- Extended infusion: 3 hours when treating resistant organisms with MIC ≥4-8 mg/L to optimize time above MIC 3, 1
- Bolus injection: 3-5 minutes is acceptable but extended infusion is preferred for serious infections 2
Critical Considerations for ICU Patients:
- Higher doses may be needed in critically ill patients with preserved renal function due to increased clearance and altered volume of distribution 1
- Therapeutic drug monitoring (TDM) is recommended for ICU patients with expected pharmacokinetic variability or clinical signs of toxicity 1
- Avoid underdosing, which is common in ICU patients with normal renal function 1
Adults with Impaired Renal Function
For adults with renal impairment, maintain the full 1 gram dose when possible but extend the dosing interval rather than reducing individual doses, as this preserves concentration-dependent bactericidal activity. 3, 4
Dosing Algorithm Based on Creatinine Clearance:
| CrCl (mL/min) | Dose | Interval |
|---|---|---|
| >50 | Full dose (500 mg or 1 g depending on indication) | Every 8 hours [2] |
| 26-50 | Full dose | Every 12 hours [2] |
| 10-25 | Half dose | Every 12 hours [2] |
| <10 | Half dose | Every 24 hours [2] |
Special Populations Requiring Modified Approaches:
Intermittent Hemodialysis (IHD):
- Approximately 50% of meropenem is removed by a single hemodialysis session 3, 5
- Administer doses after dialysis sessions to prevent premature drug removal and ensure adequate exposure 3
- Never administer before dialysis, as this leads to subtherapeutic levels 3
Continuous Renal Replacement Therapy (CRRT):
- Recommended dose: 1 gram every 8 hours to compensate for continuous drug removal 3
- CRRT removes 25-50% of meropenem, while CVVHDF removes 13-53% 3, 5
- Elimination half-life is prolonged to approximately 2.5-8.7 hours during CRRT 3
- TDM is strongly recommended for patients on CRRT to ensure adequate exposure 3, 1
Sustained Low-Efficiency Dialysis (SLED):
- Maintain the full 1 gram dose every 12 hours rather than reducing individual doses 3, 4
- Do not reduce doses below 1 gram for serious infections, as smaller doses may reduce efficacy 3
Safety Considerations and Monitoring
Neurological Toxicity:
- Trough concentrations should remain below 64 mg/L to prevent neurological toxicity, particularly seizures 3, 1, 4
- Meropenem has lower pro-convulsive activity compared to imipenem, making it safer in renal dysfunction 3
- Neurological deterioration occurs in approximately two-thirds of ICU patients when free trough concentration normalized to EUCAST breakpoint exceeds 8 1
Therapeutic Drug Monitoring Indications:
- All patients on renal replacement therapy 3, 1
- ICU patients with clinical signs of potential toxicity 1
- Critically ill patients with renal impairment to ensure adequate exposure 3
Common Pitfalls to Avoid
- Never reduce individual doses below 1 gram when treating serious infections in renal impairment; instead extend the dosing interval 3, 4
- Never administer before hemodialysis sessions, as this causes premature drug removal 3
- Do not underdose ICU patients with normal renal function due to increased clearance 1
- Consider extended infusion for resistant organisms with MIC ≥4 mg/L, even in renal impairment 3
- Monitor renal function indicators throughout treatment, though meropenem does not cause clinically significant changes in renal function 3
- Prepare new infusion bags every 6 hours if using continuous infusion due to limited stability at room temperature 1