Intramuscular Administration of Ceftriaxone 1g
Reconstitute ceftriaxone 1g powder with 2.1 mL of diluent to achieve a 350 mg/mL concentration, then inject the entire contents deep into a large muscle mass after aspirating to avoid intravascular injection. 1
Reconstitution Procedure
Diluent Selection and Volume
- Use 2.1 mL of diluent for a 1g vial to create a 350 mg/mL concentration 1
- Alternatively, use 3.6 mL of diluent for a 250 mg/mL concentration if a more dilute solution is preferred 1
- Acceptable diluents include sterile water for injection, 0.9% sodium chloride solution, or 5% dextrose solution 1
- Do not use calcium-containing diluents such as Ringer's solution or Hartmann's solution due to risk of precipitation 1
Mixing Technique
- Inject the diluent into the vial and shake thoroughly until a complete solution forms 1
- Withdraw the entire contents of the vial into the syringe to equal the total labeled dose 1
- After reconstitution, the solution color ranges from light yellow to amber, which is normal 1
Injection Technique
Site Selection and Administration
- Inject deep into the body of a relatively large muscle (such as the gluteus maximus or lateral thigh) 1
- Aspirate before injecting to help avoid unintentional injection into a blood vessel 1
Pain Reduction Strategy
- Consider using 1% lidocaine as the diluent instead of water to significantly reduce injection site pain 2
- Lidocaine does not alter the pharmacokinetics or bioavailability of ceftriaxone but considerably reduces pain intensity and frequency at the injection site 2
Stability After Reconstitution
The reconstituted solution remains stable (less than 10% potency loss) for specific timeframes depending on storage 1:
- Room temperature (25°C): 24 hours for 350 mg/mL concentration 1
- Refrigerated (4°C): 3 days for 350 mg/mL concentration 1
Pharmacokinetic Considerations
- Peak plasma concentrations of approximately 68-81 mcg/mL occur at 2-3 hours post-injection 1
- The elimination half-life is approximately 7-8 hours, allowing for once-daily dosing 1, 3
- Ceftriaxone is completely absorbed following IM administration 1, 3
- Plasma concentrations become equivalent to IV administration by 2.5 hours post-injection 4
Critical Safety Considerations
Avoid in neonates ≤28 days who require or are expected to require calcium-containing IV solutions due to fatal precipitation risk 1