Trick of the Trade: Mix Ceftriaxone IM with Lidocaine for Less Pain

Trick of the Trade: Mix Ceftriaxone IM with Lidocaine for Less Pain

2016-11-11T19:22:51+00:00

NeedleCartoonCeftriaxone is a broad-spectrum antibiotic that is frequently administered intramuscularly (IM) in emergency medicine. However, ceftriaxone IM injections hurt — A LOT! Can we do anything to minimize the pain?

Trick of the Trade

Ceftriaxone for IM use can be diluted with lidocaine 1% [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 [2], 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 two orders, i.e.,:

  1. Ceftriaxone 250 mg IM x 1
  2. Lidocaine 1% 0.9 mL, please use for ceftriaxone reconstitution (If a route for lidocaine is required, use “other” or “IM”)

Or just write,

  1. 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, 250 mg of ceftriaxone for sexually transmitted infections can be administered IV instead of IM as previously posted on ALiEM.

References

  1. Lexi-Comp Online (TM), Pediatric & Neonatal Lexi-Drugs Online (TM), Hudson, Ohio: Lexi-Comp, Inc.; January 29, 2011
  2. Antimicrob Agents Chemother. 1996 February; 40(2): 485–487. PMID: 8834905

Image courtesy of Renjith Krishnan
at FreeDigitalPhotos.net


Zlatan Coralic, PharmD

Zlatan Coralic, PharmD

Assistant Clinical Professor
Emergency Department Clinical Pharmacist
University of California, San Francisco (UCSF)