Meropenem Dilution for Intravenous Administration
Standard Dilution Volume
For intravenous infusion, dilute 1 gram of meropenem in 50-250 mL of 0.9% sodium chloride (normal saline). 1
The FDA-approved labeling specifies that meropenem injection vials may be directly reconstituted with a compatible infusion fluid, or alternatively, the vial may be reconstituted and then added to an intravenous container with appropriate infusion fluid for further dilution. 1
Concentration-Specific Recommendations
For Bolus Administration
- Reconstitute 1 gram vial with 20 mL of Sterile Water for Injection to achieve approximately 50 mg/mL concentration 1
- This concentrated solution is intended for direct bolus administration, not infusion 1
For Infusion Administration
- Concentrations ranging from 1-20 mg/mL are appropriate for intravenous infusion 1
- Most commonly used concentrations are 10-20 mg/mL for practical administration 2, 3
- For 1 gram dose: dilute in 50-100 mL of 0.9% sodium chloride (yields 10-20 mg/mL) 3
- For extended or continuous infusions: lower concentrations (1-10 mg/mL) in larger volumes (100-250 mL) are preferred 3, 4
Stability Considerations That Affect Volume Choice
The stability of meropenem is concentration-dependent—lower concentrations remain stable longer. 2, 3
- 10-20 mg/mL solutions are stable for 12 hours at room temperature (25°C) in 0.9% sodium chloride 2
- 40 mg/mL solutions are only stable for 8 hours at room temperature 2
- 1 mg/mL solutions remain stable for up to 48 hours when refrigerated at 4-5°C 3
For continuous or extended infusions (3-4 hours), using larger volumes (100-250 mL) to achieve concentrations of 4-10 mg/mL ensures adequate stability throughout the infusion period. 4
Practical Administration Protocol
For standard intermittent infusion (30 minutes):
- Dilute 1 gram in 50-100 mL of 0.9% sodium chloride 1, 3
- Infuse over 30 minutes as specified in FDA labeling 1
- Use within 1 hour at room temperature or 15 hours if refrigerated 1
For extended infusion (3-4 hours):
- Dilute 1 gram in 250 mL of 0.9% sodium chloride (4 mg/mL concentration) 4
- This concentration maintains stability throughout the extended infusion period 4
- Prepare fresh or refrigerate until use 4
Critical Pitfalls to Avoid
- Never use 5% dextrose for prolonged infusions—meropenem solutions in dextrose should be used immediately, as stability is significantly reduced compared to normal saline 1, 3
- Avoid concentrations >20 mg/mL for infusions—higher concentrations have reduced stability and may not remain potent throughout the infusion 2
- Do not mix meropenem with other drugs in the same solution, as compatibility has not been established 1
- Do not freeze reconstituted solutions—freezing destroys the drug 1