Drug interactions
Cilostazol + Phenytoin
Severity: Moderate
Cilostazol 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 CYP3A4 and other enzymes and may substantially lower cilostazol concentrations. This can lead to reduced efficacy.
What this interaction means in plain words
Cilostazol 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.
Cilostazol belongs to Cardiovascular; Phenytoin belongs to Central Nervous System.
Why it happens
Induction of CYP3A4 by phenytoin increases cilostazol clearance.
What to do
Monitor claudication symptoms and consider a different therapy if response is lost; do not stop phenytoin without neurologic input.
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 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 Cilostazol with Phenytoin?
MediHelp rates the interaction as moderate. Cilostazol 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 CYP3A4 and other enzymes and may substantially lower cilostazol concentrations. This can lead to reduced efficacy.
How serious is the interaction between Cilostazol 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: Monitor claudication symptoms and consider a different therapy if response is lost; do not stop phenytoin without neurologic input.
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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