Drug interactions
Cilostazol + Fosphenytoin
Severity: Moderate
Cilostazol and Fosphenytoin: 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
Fosphenytoin, via phenytoin, induces CYP3A4 and may lower cilostazol concentrations, reducing efficacy. The effect develops over days to weeks.
What this interaction means in plain words
Cilostazol and Fosphenytoin 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.
Cilostazol belongs to Cardiovascular; Fosphenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induction of CYP3A4 increases cilostazol metabolism.
What to do
Monitor claudication symptoms and consider a dose adjustment if response declines; reassess when fosphenytoin is stopped.
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 Cilostazol
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 Cilostazol with Fosphenytoin?
MediHelp rates the interaction as moderate. Cilostazol and Fosphenytoin 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, via phenytoin, induces CYP3A4 and may lower cilostazol concentrations, reducing efficacy. The effect develops over days to weeks.
How serious is the interaction between Cilostazol and Fosphenytoin?
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 claudication symptoms and consider a dose adjustment if response declines; reassess when fosphenytoin is stopped.
What other medicines interact with Cilostazol?
MediHelp also lists interactions of Cilostazol with, for example, Abrocitinib, Anagrelide, Betrixaban. The full list is on the Cilostazol page.
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