Capecitabine and Phenytoin interaction
Capecitabine and Phenytoin: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Capecitabine (XELODA) label · effective 2026-02-05
Vitamin K antagonists: Monitor INR more frequently and dose adjust oral vitamin K antagonist as appropriate Phenytoin : Closely monitor phenytoin levels in patients taking XELODA concomitantly with phenytoin and adjust the phenytoin dose as appropriate.
Phenytoin XELODA may increases exposure of phenytoin, which may increase the risk of adverse reactions related to phenytoin.
Closely monitor phenytoin levels and refer to the prescribing information of phenytoin for dosage adjustment, as appropriate, when XELODA is used concomitantly with phenytoin.
From the Phenytoin label · effective 2024-12-24
…Antiepileptic drugs Ethosuximide, felbamate, oxcarbazepine, methsuximide, topiramate Azoles Fluconazole, ketoconazole, itraconazole, miconazole, voriconazole Antineoplastic agents Capecitabine, fluorouracil Antidepressants Fluoxetine, fluvoxamine, sertraline Gastric acid reducing agents H 2 antagonists (cimetidine), omeprazole Sulfonamides Sulfamethizole, sulfaphenazole,…
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.