Drug interactions
Fosphenytoin + Mebendazole
Severity: Moderate
Fosphenytoin and Mebendazole: 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, the active form of fosphenytoin, reduces mebendazole concentrations and may compromise treatment of tissue-dwelling parasites. Mebendazole may also affect phenytoin levels in some reports.
What this interaction means in plain words
Fosphenytoin and Mebendazole 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.
Fosphenytoin belongs to Central Nervous System; Mebendazole belongs to Anti Parasitic.
Why it happens
Phenytoin induces hepatic CYP enzymes, increasing mebendazole metabolism.
What to do
For systemic helminth infections, monitor treatment response and consider an alternative or adjusted mebendazole regimen; monitor phenytoin levels.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Fosphenytoin and Mebendazole, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Mebendazole
- Deferiprone + Mebendazole Major
- Mebendazole + Metronidazole Major
- Acalabrutinib + Mebendazole Moderate
- Carbamazepine + Mebendazole Moderate
- Ethotoin + Mebendazole Moderate
- Mebendazole + Phenytoin Moderate
Other interactions of Fosphenytoin
- Dronedarone + Fosphenytoin Contraindicated
- Fosphenytoin + Ledipasvir-sofosbuvir Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Fosphenytoin with Mebendazole?
MediHelp rates the interaction as moderate. Fosphenytoin and Mebendazole 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, the active form of fosphenytoin, reduces mebendazole concentrations and may compromise treatment of tissue-dwelling parasites. Mebendazole may also affect phenytoin levels in some reports.
How serious is the interaction between Fosphenytoin and Mebendazole?
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 systemic helminth infections, monitor treatment response and consider an alternative or adjusted mebendazole regimen; monitor phenytoin levels.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
