Drug interactions
Cilostazol + Ritonavir
Severity: Moderate
Cilostazol and Ritonavir: 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
Ritonavir can substantially increase cilostazol exposure, raising risk of tachycardia, palpitations, headache and diarrhea.
What this interaction means in plain words
Cilostazol and Ritonavir 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; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir is a strong CYP3A4 inhibitor that reduces cilostazol clearance.
What to do
Reduce cilostazol to 50 mg twice daily with strong CYP3A4 inhibitors and monitor heart rate and tolerability.
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 Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Cilostazol with Ritonavir?
MediHelp rates the interaction as moderate. Cilostazol and Ritonavir 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. Ritonavir can substantially increase cilostazol exposure, raising risk of tachycardia, palpitations, headache and diarrhea.
How serious is the interaction between Cilostazol and Ritonavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Reduce cilostazol to 50 mg twice daily with strong CYP3A4 inhibitors and monitor heart rate and tolerability.
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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