Drug interactions
Mebendazole + Phenytoin
Severity: Moderate
Mebendazole and Phenytoin: 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
Phenytoin induces hepatic enzymes and can lower mebendazole plasma concentrations substantially. This may lead to treatment failure, particularly in systemic or tissue helminth infections such as hydatid disease or neurocysticercosis where adequate exposure is essential.
What this interaction means in plain words
Mebendazole and Phenytoin 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.
Mebendazole belongs to Anti Parasitic; Phenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces hepatic CYP enzymes, increasing the metabolism of mebendazole.
What to do
For tissue-invasive infections, monitor clinical and imaging response and consider mebendazole dose adjustment with drug-level monitoring, or use a non-inducing anticonvulsant. For intestinal infections the effect is usually of little consequence.
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 Mebendazole
- Deferiprone + Mebendazole Major
- Mebendazole + Metronidazole Major
- Acalabrutinib + Mebendazole Moderate
- Carbamazepine + Mebendazole Moderate
- Ethotoin + Mebendazole Moderate
- Fosphenytoin + Mebendazole Moderate
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 Mebendazole with Phenytoin?
MediHelp rates the interaction as moderate. Mebendazole and Phenytoin 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. Phenytoin induces hepatic enzymes and can lower mebendazole plasma concentrations substantially. This may lead to treatment failure, particularly in systemic or tissue helminth infections such as hydatid disease or neurocysticercosis where adequate exposure is essential.
How serious is the interaction between Mebendazole and Phenytoin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: For tissue-invasive infections, monitor clinical and imaging response and consider mebendazole dose adjustment with drug-level monitoring, or use a non-inducing anticonvulsant. For intestinal infections the effect is usually of little consequence.
What other medicines interact with Mebendazole?
MediHelp also lists interactions of Mebendazole with, for example, Deferiprone, Metronidazole, Acalabrutinib. The full list is on the Mebendazole page.
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