Drug interactions
Capecitabine + Ethotoin
Severity: Moderate
Capecitabine and Ethotoin: moderate interaction.
Last updated
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.
Summary
Capecitabine is converted to fluorouracil, which has been associated with raised phenytoin levels, and ethotoin is a related hydantoin. Elevated levels could cause ataxia, nystagmus and sedation. Evidence for ethotoin is extrapolated from phenytoin.
What this interaction means in plain words
Capecitabine and Ethotoin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Probably reduced hydantoin metabolism, possibly through CYP2C9 inhibition; the mechanism is not firmly established.
What to do
Monitor for hydantoin toxicity and anticonvulsant response when starting or stopping capecitabine. Reduce the ethotoin dose if toxicity appears.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Capecitabine
Frequently asked questions
Can I take Capecitabine with Ethotoin?
MediHelp rates the interaction as moderate. Capecitabine and Ethotoin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Capecitabine is converted to fluorouracil, which has been associated with raised phenytoin levels, and ethotoin is a related hydantoin. Elevated levels could cause ataxia, nystagmus and sedation. Evidence for ethotoin is extrapolated from phenytoin.
How serious is the interaction between Capecitabine and Ethotoin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for hydantoin toxicity and anticonvulsant response when starting or stopping capecitabine. Reduce the ethotoin dose if toxicity appears.
What other medicines interact with Capecitabine?
MediHelp also lists interactions of Capecitabine with, for example, Adenovirus types 4 and 7 live, Arsenic trioxide, Axicabtagene ciloleucel. The full list is on the Capecitabine page.
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