Meropenem Dosing for Urinary Tract Infections and Chest Infections
For urinary tract infections, the recommended dosage of meropenem is 1 gram IV every 8 hours for 5-7 days, while for chest infections (pneumonia), meropenem 1 gram IV every 8 hours is recommended with treatment duration of at least 7 days. 1, 2
Urinary Tract Infections (UTIs)
Standard Dosing:
- For complicated UTIs: 1 gram IV every 8 hours 1
- Treatment duration: 5-7 days for most complicated UTIs 1, 2
- Extended infusion over 3 hours is recommended if the pathogen's meropenem MIC is ≥8 mg/L 1
Special Considerations:
- In critically ill patients with healthcare-associated UTIs: meropenem 1 gram IV every 8 hours 2
- For carbapenem-resistant organisms causing UTIs, alternative options include:
Clinical Evidence:
- The TANGO I randomized clinical trial demonstrated that meropenem-vaborbactam was non-inferior and potentially superior to piperacillin-tazobactam for complicated UTIs, with overall success rates of 98.4% vs 94.0% respectively 3
- Meropenem reaches peak plasma concentrations of approximately 30 mg/L after administration of a standard 1 gram IV dose 4
Chest Infections (Pneumonia)
Standard Dosing:
- For community-acquired pneumonia in critically ill patients: meropenem 1 gram IV every 8 hours 2
- For healthcare-associated pneumonia: meropenem 1 gram IV every 8 hours 2
- Treatment duration: at least 7 days, individualized based on clinical response 2
Special Considerations:
- For severe infections with resistant organisms, combination therapy may be considered based on susceptibility testing 2, 1
- In patients with Acinetobacter baumannii pneumonia, high-dose meropenem (2 grams every 8 hours) may be considered 2
Dosage Adjustments
Renal Impairment:
- Meropenem elimination half-life is prolonged in patients with renal insufficiency and correlates with creatinine clearance 4
- Dosage adjustments should be made based on creatinine clearance 4
- For patients on continuous venovenous hemofiltration (CVVH), 1 gram IV every 8 hours is recommended 5
Important Clinical Considerations:
- Meropenem has a broad spectrum of activity against Gram-positive and Gram-negative bacteria 6
- Unlike imipenem, meropenem is relatively stable to hydrolysis by dehydropeptidase I (DHP-I), eliminating the need for co-administration with cilastatin 4
- Meropenem has a volume of distribution of approximately 21L, indicating predominantly extracellular distribution 4
- Up to 70% of meropenem is recovered unchanged in urine 4
Common Pitfalls and Caveats:
- Resistance to meropenem may emerge during treatment of Pseudomonas aeruginosa infections 6
- Stenotrophomonas maltophilia is typically resistant to meropenem 6
- Indiscriminate use of carbapenems promotes resistance development 6
- For mixed bacterial infections, meropenem should be considered when aerobic gram-negative bacteria are not susceptible to other beta-lactam agents 6