Cephalosporins

This information on drug interactions with antimicrobials is intended for use as a guide and not as a complete reference source

Antibiotic Class

Interacting Drug

Comment

Cephalosporins e.g.

Cefaclor
Cefixime
Cefuroxime
Cefalexin
Cefazolin
Ceftriaxone

Zinc

With cefalexin: risk of reduced bioavailability and efficacy. Separate the doses by 3 hours or more to avoid interaction.

Warfarin

Penicillins and cephalosporins are preferred alternatives when patients are on warfarin. Documented reports of bleeding incidents with these antibiotics are rare even though a theoretical risk exists. Monitor INR during and after antimicrobial treatment and adjust warfarin dose as necessary.