Meropenem Cannot Be Given Intramuscularly
Meropenem is FDA-approved for intravenous administration only and should not be given intramuscularly. 1
FDA-Approved Routes of Administration
The FDA prescribing information for meropenem explicitly specifies only intravenous routes:
- IV infusion over 15-30 minutes (standard method) 1
- IV bolus injection over 3-5 minutes (for doses of 1 gram) 1
No intramuscular formulation or dosing guidance exists in the FDA label for meropenem. 1
Why This Matters Clinically
While some older research literature from the 1990s mentions intramuscular administration of meropenem in investigational settings 2, 3, 4, this route was never approved by regulatory agencies and is not part of standard clinical practice. The FDA label contains no instructions for IM preparation, dosing, or administration. 1
Alternative Carbapenem for IM Use
If intramuscular carbapenem administration is clinically necessary (e.g., when IV access is unavailable), ertapenem is the appropriate choice:
- Ertapenem can be administered intramuscularly at 1g daily 5, 6
- IM ertapenem has demonstrated efficacy in multidrug-resistant tuberculosis treatment (when combined with amoxicillin-clavulanate) 5, 6
- IM ertapenem 1g has shown non-inferiority to ceftriaxone for anogenital gonorrhea 6
- The longer half-life of ertapenem makes once-daily IM dosing feasible, unlike meropenem which requires every-8-hour dosing 5
Clinical Pitfalls to Avoid
- Do not attempt to reconstitute meropenem for IM injection - the FDA label provides no guidance for this route, and tissue tolerance/absorption data are lacking 1
- Do not confuse meropenem with ertapenem - while both are carbapenems, only ertapenem has an approved IM formulation 5, 6
- If IV access is truly unavailable and a carbapenem is essential, establish vascular access or switch to ertapenem IM rather than attempting off-label IM meropenem 6