Capecitabine and Warfarin: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Capecitabine and Warfarin unless specifically directed by your doctor.
How Capecitabine interacts with Warfarin
Capecitabine and its metabolite 5-FU inhibit CYP2C9-mediated warfarin metabolism and impair vitamin K-dependent clotting factor synthesis, markedly increasing INR.
What you should do
Monitor INR at least weekly during capecitabine therapy and for 1 month after discontinuation; anticipate substantial warfarin dose reductions.
Key facts
Severity
Major — avoid combination
Mechanism
Capecitabine and its metabolite 5-FU inhibit CYP2C9-mediated warfarin metabolism and impair vitamin K-dependent clotting...
Action
Monitor INR at least weekly during capecitabine therapy and for 1 month after discontinuation; anticipate substantial wa...
Frequently asked questions
Can I take Capecitabine and Warfarin together?
No — this combination should generally be avoided. Monitor INR at least weekly during capecitabine therapy and for 1 month after discontinuation; anticipate substantial warfarin dose reductions.
What is the severity of this interaction?
The interaction between Capecitabine and Warfarin is classified as Major — avoid combination. Capecitabine and its metabolite 5-FU inhibit CYP2C9-mediated warfarin metabolism and impair vitamin K-dependent clotting factor synthesis, markedly increasing INR.
What should I do if I'm prescribed both?
Monitor INR at least weekly during capecitabine therapy and for 1 month after discontinuation; anticipate substantial warfarin dose reductions. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.