Drug interactions
Istradefylline + Verapamil
Severity: Moderate
Istradefylline and Verapamil: 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
Istradefylline at 40 mg/day can inhibit CYP3A4 and P-gp, increasing verapamil exposure and risk of hypotension, bradycardia and conduction delay. This effect was not seen at 20 mg/day.
What this interaction means in plain words
Istradefylline and Verapamil 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.
Istradefylline belongs to Central Nervous System; Verapamil belongs to Cardiovascular.
Why it happens
Istradefylline inhibits CYP3A4 and P-glycoprotein at higher doses, reducing verapamil clearance and increasing absorption.
What to do
Monitor blood pressure, heart rate and ECG, particularly if istradefylline 40 mg/day is used. Reduce the verapamil dose if excess effect develops.
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 Verapamil
- Dofetilide + Verapamil Contraindicated
- Flibanserin + Verapamil Contraindicated
- Lomitapide + Verapamil Contraindicated
- Lonafarnib + Verapamil Contraindicated
- Pimozide + Verapamil Contraindicated
- Acebutolol + Verapamil Major
Other interactions of Istradefylline
Frequently asked questions
Can I take Istradefylline with Verapamil?
MediHelp rates the interaction as moderate. Istradefylline and Verapamil 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. Istradefylline at 40 mg/day can inhibit CYP3A4 and P-gp, increasing verapamil exposure and risk of hypotension, bradycardia and conduction delay. This effect was not seen at 20 mg/day.
How serious is the interaction between Istradefylline and Verapamil?
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 blood pressure, heart rate and ECG, particularly if istradefylline 40 mg/day is used. Reduce the verapamil dose if excess effect develops.
What other medicines interact with Verapamil?
MediHelp also lists interactions of Verapamil with, for example, Dofetilide, Flibanserin, Lomitapide. The full list is on the Verapamil page.
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