Ceftriaxone is a broad-spectrum antibiotic that is frequently administered intramuscularly (IM) in emergency medicine. However, these injections hurt — A LOT! Can we do anything to minimize the pain?
Trick of the Trade: Give ceftriaxone IM with lidocaine
Ceftriaxone for IM use can be diluted with lidocaine 1% :
- Ceftriaxone 250 mg vial – mix with 0.9 mL of lidocaine 1% = 250 mg/mL
- Ceftriaxone 1000 mg vial – mix with 2.1 mL of lidocaine 1% = 350 mg/mL
What do the patients say?
In a double-blind crossover study , patients receiving IM ceftriaxone diluted with lidocaine 1% experienced 50% less pain compared to using sterile water for injection as a diluent. Using a 100 mm visual analog scale shortly after the shot, patients rated lidocaine-ceftriaxone pain as 25 mm compared to 50 mm for water-ceftriaxone. There was significant pain relief sustained up to 1 hour later.
How to Order
Depending on your institution, you may need to write 2 orders, i.e.,:
- Ceftriaxone 250 mg IM x 1
- Lidocaine 1% 0.9 mL, please use for ceftriaxone reconstitution (If a route for lidocaine is required, use “other” or “IM”)
Or just write:
- Ceftriaxone 250 mg IM x 1, mixed with lidocaine 1%
Please check with your local pharmacist to see what is preferred in your emergency department.
And a reminder, if you have a functioning IV line, ceftriaxone for sexually transmitted infections can be administered IV instead of IM as previously posted on ALiEM. Also read more about the 2020 CDC updated guideline on gonorrhea treatment, which increased the dose of ceftriaxone from 250 to 500 mg because of the increased rate of resistance.
- Lexi-Comp Online (TM), Pediatric & Neonatal Lexi-Drugs Online (TM), Hudson, Ohio: Lexi-Comp, Inc.; January 29, 2011
- Antimicrob Agents Chemother. 1996 February; 40(2): 485–487. PMID: 8834905
Image courtesy of Renjith Krishnan