Rocephin 500mg IM Reconstitution with Normal Saline
For intramuscular administration of 500mg Rocephin (ceftriaxone), add 1.8 mL of normal saline to achieve a concentration of 250 mg/mL, or add 1.0 mL to achieve a concentration of 350 mg/mL 1.
Reconstitution Instructions
The FDA-approved labeling provides two concentration options for IM administration of the 500mg vial:
- 250 mg/mL concentration: Add 1.8 mL of diluent
- 350 mg/mL concentration: Add 1.0 mL of diluent
Both concentrations are bioequivalent and equally effective 2. The more concentrated 350 mg/mL solution requires a smaller injection volume (1.4 mL total), which may be more comfortable for the patient, while the 250 mg/mL solution (2.0 mL total) is the traditional formulation.
Administration Technique
After reconstitution 1:
- Inject the diluent into the vial and shake thoroughly to form solution
- Withdraw entire contents into syringe to equal the total labeled dose
- Inject deep into a large muscle mass (gluteus maximus or lateral thigh)
- Aspirate before injection to avoid inadvertent intravascular administration
Important Compatibility Notes
Do not use diluents containing calcium (such as Ringer's solution or Hartmann's solution) for reconstitution, as particulate formation can result 1. Normal saline (0.9% sodium chloride) is the appropriate diluent for IM administration.
Stability After Reconstitution
Once reconstituted with normal saline at either concentration 1:
- Room temperature (25°C): Stable for 2 days (250 mg/mL) or 24 hours (350 mg/mL)
- Refrigerated (4°C): Stable for 10 days (250 mg/mL) or 3 days (350 mg/mL)
The solution color ranges from light yellow to amber depending on storage duration and concentration—this is normal and does not require protection from light after reconstitution.