Ceftriaxone and Lactated Ringer Compatibility

Today’s pearl addresses the safety of ceftriaxone administration in a patient also ordered for lactated ringers.

Will this precipitate any problems?

With increasing use of balanced solutions for fluid resuscitation, Lactated Ringer’s popularity is at an all-time high. Ceftriaxone is one of our more commonly ordered IV antibiotics and is appropriate broad-spectrum coverage for many suspected infections, including CAP. LR contains calcium (200 mg CaCl per liter), which can precipitate when mixed with ceftriaxone causing incompatibility.

Question: What do you do when the electronic medical record warns against giving LR and ceftriaxone together? Ignore it? Substitute an even broader-spectrum antibiotic such as cefepime?

Answer: In patients > 28 days old, the alert can be bypassed. According to the FDA-approved package insert (and several other references), ceftriaxone can safely be administered as long as it is given in a separate IV line from LR. It could also be given through the same IV line as long as there was sufficient flushing of the line between the ceftriaxone and LR administrations. In neonates ≤ 28 days old, concomitant use of ceftriaxone and intravenous calcium-containing products is contraindicated, even if given in separate lines.

Bonus pearl: LR is also safe in hyperkalemia.


Author: Bryan D. Hayes, PharmD

Attending Pharmacist, Emergency Medicine and Toxicology, Massachusetts General Hospital; Assistant Professor of EM, Harvard Medical School

2 thoughts on “Ceftriaxone and Lactated Ringer Compatibility”

  1. Dr. Hayes: Would you provide your thoughts regarding IV compatibility of Ceftriaxone and LR during y-site administration in regards to a recent Hospital Pharmacy article (DOI: 10.1177/0018578719888913)? Do you feel this study provides enough data to make the assumption that ceftriaxone and LR are compatible during y-site administration of ceftriaxone thru a free flowing LR IV?


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