Drug interactions
Ethotoin + Fluorouracil
Severity: Moderate
Ethotoin and Fluorouracil: 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
Fluorouracil has been associated with raised serum levels of phenytoin-type anticonvulsants, and ethotoin is a related hydantoin. Elevated levels could cause nystagmus, ataxia, sedation and confusion. Evidence for ethotoin itself is extrapolated from phenytoin.
What this interaction means in plain words
Ethotoin and Fluorouracil 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 inhibition of CYP2C9; the mechanism is not firmly established.
What to do
Monitor for signs of hydantoin toxicity and check anticonvulsant levels or clinical response when starting or stopping fluorouracil. 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 Fluorouracil
Frequently asked questions
Can I take Ethotoin with Fluorouracil?
MediHelp rates the interaction as moderate. Ethotoin and Fluorouracil 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. Fluorouracil has been associated with raised serum levels of phenytoin-type anticonvulsants, and ethotoin is a related hydantoin. Elevated levels could cause nystagmus, ataxia, sedation and confusion. Evidence for ethotoin itself is extrapolated from phenytoin.
How serious is the interaction between Ethotoin and Fluorouracil?
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 signs of hydantoin toxicity and check anticonvulsant levels or clinical response when starting or stopping fluorouracil. Reduce the ethotoin dose if toxicity appears.
What other medicines interact with Fluorouracil?
MediHelp also lists interactions of Fluorouracil with, for example, Adenovirus types 4 and 7 live, Axicabtagene ciloleucel, Belatacept. The full list is on the Fluorouracil page.
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