Drug interactions
Fexinidazole + Phenytoin
Severity: Major
Fexinidazole and Phenytoin: major 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
Phenytoin may alter the exposure of fexinidazole's active metabolites, which are linked to QT prolongation, and could also reduce treatment efficacy. The net effect is uncertain and may impair safe use.
What this interaction means in plain words
Fexinidazole and Phenytoin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
CYP enzyme induction by phenytoin changes fexinidazole metabolism, though the direction and net effect are not firmly established.
What to do
Avoid the combination and use a non-inducing anticonvulsant. If it cannot be avoided, obtain an ECG and monitor electrolytes.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Frequently asked questions
Can I take Fexinidazole with Phenytoin?
MediHelp rates the interaction as major. Fexinidazole and Phenytoin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Phenytoin may alter the exposure of fexinidazole's active metabolites, which are linked to QT prolongation, and could also reduce treatment efficacy. The net effect is uncertain and may impair safe use.
How serious is the interaction between Fexinidazole and Phenytoin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and use a non-inducing anticonvulsant. If it cannot be avoided, obtain an ECG and monitor electrolytes.
What other medicines interact with Phenytoin?
MediHelp also lists interactions of Phenytoin with, for example, Artemether / lumefantrine, Bictegravir, Cabotegravir. The full list is on the Phenytoin page.
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