Drug interactions
ceftriaxone + warfarin
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Overview
Ceftriaxone may potentiate warfarin’s anticoagulant effect, increasing INR and bleeding risk.
Mechanism of action
Suppression of vitamin K–producing gut flora and cephalosporin-associated hypoprothrombinemia; possible displacement of protein-bound warfarin; no significant CYP effect.
Clinical management
Monitor INR closely (e.g., within 48–72 h of starting and after stopping ceftriaxone); adjust warfarin dose to target INR; counsel on bleeding; consider vitamin K if INR markedly elevated or bleeding.
Drug reference
References
- Ceftriaxone Injection Prescribing Information — FDA Label
- Warfarin (Coumadin) Prescribing Information — FDA Label
- Warfarin: Drug Interactions (cephalosporins) — Lexicomp
Frequently asked questions
Can I take ceftriaxone with warfarin?
The interaction is rated: Moderate. Ceftriaxone may potentiate warfarin’s anticoagulant effect, increasing INR and bleeding risk.
How serious is the interaction between ceftriaxone and warfarin?
The interaction is rated: Moderate. Evidence level: High.
How is the interaction between ceftriaxone and warfarin managed?
Monitor INR closely (e.g., within 48–72 h of starting and after stopping ceftriaxone); adjust warfarin dose to target INR; counsel on bleeding; consider vitamin K if INR markedly elevated or bleeding.
Why do ceftriaxone and warfarin interact?
Suppression of vitamin K–producing gut flora and cephalosporin-associated hypoprothrombinemia; possible displacement of protein-bound warfarin; no significant CYP effect.
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