Capecitabine and Warfarin interaction
Capecitabine and Warfarin: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Capecitabine (XELODA) label · effective 2026-02-05
WARNING: SERIOUS ADVERSE REACTIONS OR DEATH IN PATIENTS WITH COMPLETE DPD DEFICIENCY and INCREASED RISK OF BLEEDING WITH CONCOMITANT USE OF VITAMIN K ANTAGONISTS Increased risk of serious adverse reactions or death in patients with complete DPD deficiency • Test patients for genetic variants of DPYD prior to initiating XELODA unless immediate treatment is necessary.
Increased risk of bleeding with concomitant use of Vitamin K antagonists • Altered coagulation parameters and/or bleeding, including death, have been reported in patients taking XELODA concomitantly with oral vitamin K antagonists, such as warfarin [see Warnings and Precautions (5.2) , Drug Interactions (7.2) ] .
• Clinically significant increases in prothrombin time (PT) and international normalized ratio (INR) have been reported in patients who were on stable doses of a vitamin K antagonist at the time XELODA was introduced.
• Monitor INR more frequently and adjust the dose of the vitamin K antagonist as appropriate [see Drug Interactions (7.2) ].
WARNING: SERIOUS ADVERSE REACTIONS OR DEATH IN PATIENTS WITH COMPLETE DPD DEFICIENCY and BLEEDING WITH CONCOMITANT USE OF VITAMIN K ANTAGONISTS See full prescribing information for complete boxed warning .
From the Warfarin (Warfarin Sodium) label · effective 2026-06-24
Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol,…
Inhibitors of CYP2C9, 1A2, and/or 3A4 have the potential to increase the effect (increase INR) of warfarin by increasing the exposure of warfarin.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.