Drug interactions
Cilostazol + Saquinavir
Severity: Major
Cilostazol and Saquinavir: major interaction.
Last updated Sources: UK SmPC
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
Saquinavir, usually boosted with ritonavir, inhibits CYP3A4 and is expected to raise cilostazol levels. This may cause tachycardia, palpitations and headache, and saquinavir also prolongs the QT interval.
What this interaction means in plain words
Cilostazol and Saquinavir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Saquinavir and its ritonavir booster inhibit CYP3A4, decreasing cilostazol metabolism.
What to do
Reduce cilostazol to 50 mg twice daily or use an alternative, and monitor heart rate and ECG.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Cilostazol
Frequently asked questions
Can I take Cilostazol with Saquinavir?
MediHelp rates the interaction as major. Cilostazol and Saquinavir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Saquinavir, usually boosted with ritonavir, inhibits CYP3A4 and is expected to raise cilostazol levels. This may cause tachycardia, palpitations and headache, and saquinavir also prolongs the QT interval.
How serious is the interaction between Cilostazol and Saquinavir?
MediHelp rates it major, 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 or use an alternative, and monitor heart rate and ECG.
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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