Meropenem Dosing
For adults with normal renal function, administer meropenem 500 mg IV every 8 hours for complicated skin/soft tissue infections or 1 gram IV every 8 hours for intra-abdominal infections, given as a 15-30 minute infusion or 3-5 minute bolus. 1
Standard Adult Dosing (Normal Renal Function)
- Complicated skin/soft tissue infections: 500 mg IV every 8 hours
- Complicated intra-abdominal infections: 1 gram IV every 8 hours
- Pseudomonas aeruginosa infections: 1 gram IV every 8 hours (regardless of infection site)
- Administration: 15-30 minute infusion OR 3-5 minute bolus for 1 gram doses 1
Renal Impairment Dosing
Dose reduction is mandatory when creatinine clearance falls below 50 mL/min 1:
| Creatinine Clearance | Dose | Interval |
|---|---|---|
| >50 mL/min | Standard dose (500 mg or 1 g) | Every 8 hours |
| 26-50 mL/min | Standard dose | Every 12 hours |
| 10-25 mL/min | Half standard dose | Every 12 hours |
| <10 mL/min | Half standard dose | Every 24 hours |
Critical Caveat for Dialysis Patients
There is inadequate data for dosing in hemodialysis or peritoneal dialysis patients 1. However, research evidence suggests:
- Hemodialysis: Approximately 30% of meropenem is removed during a standard HD session 2
- Risk of neurotoxicity: Even the "recommended" 500 mg daily dose may cause seizures in HD patients, particularly those with lower body mass 2
- Continuous renal replacement therapy (CRRT):
Pediatric Dosing
Children ≥3 Months with Normal Renal Function
| Indication | Dose | Maximum | Interval |
|---|---|---|---|
| Complicated skin/soft tissue | 10 mg/kg | 500 mg | Every 8 hours |
| Intra-abdominal infections | 20 mg/kg | 1 gram | Every 8 hours |
| Meningitis | 40 mg/kg | 2 grams | Every 8 hours |
| P. aeruginosa skin infections | 20 mg/kg | 1 gram | Every 8 hours |
Infants <3 Months (Intra-abdominal Infections Only)
| Gestational/Postnatal Age | Dose | Interval |
|---|---|---|
| <32 weeks GA, PNA <2 weeks | 20 mg/kg | Every 12 hours |
| <32 weeks GA, PNA ≥2 weeks | 20 mg/kg | Every 8 hours |
| ≥32 weeks GA, PNA <2 weeks | 20 mg/kg | Every 8 hours |
| ≥32 weeks GA, PNA ≥2 weeks | 30 mg/kg | Every 8 hours |
- Administration: 30-minute infusion only 1
Special Populations
ECMO Patients
For critically ill adults on ECMO with or without RRT: 1 gram every 8 hours as continuous infusion 6. This regimen:
- Achieves 100% probability of target attainment (Cmin ≥2 mg/L)
- Maintains <4% risk of toxic concentrations (Cmin >45 mg/L)
- Remains effective across creatinine clearance 60-130 mL/min and ECMO flow rates 4-6 L/min 6
Key principle: ECMO flow rate affects volume of distribution, but renal function and RRT remain the primary determinants of meropenem clearance 6, 7
Augmented Renal Clearance
Patients with augmented renal clearance may require intensified dosing (e.g., 1 gram every 6-8 hours or prolonged infusion) to achieve pharmacodynamic targets, particularly against pathogens with MIC ≥4 mg/L 8
Extended vs. Intermittent Infusion
Extended infusion (≥3 hours) is associated with reduced acute kidney injury when combined with colistimethate sodium 9:
- 24.7% vs 39.7% AKI incidence (p=0.006)
- Lower mortality (19.2% vs 28.1%, p=0.021)
- Reduced need for RRT (5.5% vs 12.3%, p=0.034)
Important Warnings
- Seizure risk: Particularly in renal impairment, elderly, CNS disorders, or when combined with valproic acid 1
- Valproic acid interaction: Meropenem reduces valproic acid levels by 50-100%, increasing breakthrough seizure risk—avoid this combination 1
- Probenecid: Inhibits renal excretion of meropenem; concomitant use not recommended 1
- MIC considerations: At MIC ≥8 mg/L, even high-dose regimens may fail to achieve stringent PK/PD targets 8