Meropenem 3-Hour Infusion Dilution Protocol
For a 3-hour infusion of 1 gram Meropenem (reconstituted in 20ml sterile water), dilute in 100ml of 0.9% sodium chloride (normal saline) for a total volume of approximately 120ml.
Reconstitution and Dilution Steps
Initial Reconstitution: Add 20ml sterile water to the 1 gram Meropenem vial to dissolve the powder 1
Final Dilution: Transfer the reconstituted solution (20ml) into 100ml of 0.9% sodium chloride 1, 2
- This creates a final concentration of approximately 8 mg/ml
- Total infusion volume: ~120ml
Administration Rate: Infuse over 3 hours (approximately 40 ml/hour) 1, 2
Critical Stability Considerations
Meropenem must be used within specific timeframes after reconstitution due to degradation:
- At room temperature (22°C): Meropenem maintains >90% concentration for approximately 7.4 hours 3
- At elevated temperatures (32-37°C): Concentration drops to 88% by 8 hours 4
- For a 3-hour infusion, stability is adequate at standard room temperature 3, 4
Clinical Context for Extended Infusion
The 3-hour infusion strategy is specifically recommended for carbapenem-resistant organisms where the Meropenem MIC is ≥8 mg/L, as extended infusion maximizes time-dependent bactericidal activity 1. Standard dosing for this indication is 1 gram IV every 8 hours by extended infusion 1.
Important Compatibility Notes
- Meropenem is physically compatible with 0.9% sodium chloride for Y-site administration 2
- Do not mix with alkaline solutions (similar carbapenem precautions apply) 1
- The solution should be prepared using aseptic technique 1
Common Pitfalls to Avoid
- Do not prepare more than 7 hours in advance if storing at room temperature, as concentrations drop below 90% 3
- Avoid storage in non-air-conditioned tropical environments where temperatures exceed 32°C, as degradation accelerates significantly 4
- Do not attempt 24-hour continuous infusion, as meropenem stability is insufficient 3