Should 10 cc of sterile solution be used to reconstitute 1g of Rocephin (ceftriaxone) for IM injection?

Reconstitution of Ceftriaxone for IM Injection

Yes, 10 cc of sterile solution should be used to reconstitute 1g of Rocephin (ceftriaxone) for IM injection.

Proper Reconstitution Guidelines

According to the FDA drug label for ceftriaxone, proper reconstitution for intramuscular administration requires specific diluent volumes based on the desired final concentration 1:

• For a 250 mg/mL concentration: Use 3.6 mL of diluent for 1g vial
• For a 350 mg/mL concentration: Use 2.1 mL of diluent for 1g vial
• For a more dilute solution (approximately 100 mg/mL): Use 9.6 mL of diluent for 1g vial

Therefore, using 10 cc (10 mL) of sterile solution would result in a concentration of approximately 100 mg/mL, which is an appropriate concentration for IM injection, especially when considering patient comfort.

Diluent Selection

The FDA label indicates several compatible diluents for IM administration of ceftriaxone 1:

• Sterile Water for Injection
• 0.9% Sodium Chloride Solution
• 5% Dextrose Solution
• Bacteriostatic Water with 0.9% Benzyl Alcohol
• 1% Lidocaine Solution (without epinephrine)

Clinical Considerations

Pain Management

Research has shown that using 1% lidocaine as a diluent can significantly reduce injection pain compared to sterile water 2. This is an important consideration for patient comfort, as ceftriaxone IM injections are known to be painful.

Stability Considerations

After reconstitution with 10 mL of diluent to achieve a 100 mg/mL concentration, the stability varies by diluent type 1:

• With sterile water: Stable for 2 days at room temperature or 10 days refrigerated
• With 0.9% sodium chloride: Stable for 2 days at room temperature or 10 days refrigerated
• With 5% dextrose: Stable for 2 days at room temperature or 10 days refrigerated

Administration Technique

• Inject well within the body of a relatively large muscle
• Aspiration is recommended to avoid unintentional injection into a blood vessel
• The larger volume (10 mL) may need to be divided and administered at two separate injection sites for better patient tolerance

Common Pitfalls to Avoid

1. Calcium-containing diluents: Never use diluents containing calcium, such as Ringer's solution or Hartmann's solution, as particulate formation can result 1

2. Inadequate mixing: After adding diluent to the vial, shake thoroughly to ensure complete dissolution

3. Improper storage: After reconstitution, protect from light and store according to the stability guidelines for the specific diluent used

4. Inappropriate concentration: Using too little diluent (resulting in a highly concentrated solution) can increase injection pain and tissue irritation

Using 10 cc of sterile solution provides an appropriate concentration that balances stability, administration volume, and patient comfort for IM administration of 1g ceftriaxone.