Drug interactions
Phentolamine + Verapamil
Severity: Moderate
Phentolamine 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
Both drugs lower blood pressure by vasodilation, so combined use can cause pronounced hypotension and reflex tachycardia. Risk is greatest with parenteral phentolamine.
What this interaction means in plain words
Phentolamine 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.
Phentolamine belongs to Cardiovascular; Verapamil belongs to Cardiovascular.
Why it happens
Additive vasodilation through calcium channel blockade and alpha-adrenergic blockade.
What to do
Monitor blood pressure and heart rate closely when given together. Reduce doses or space administration if hypotension occurs.
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 Phentolamine
Frequently asked questions
Can I take Phentolamine with Verapamil?
MediHelp rates the interaction as moderate. Phentolamine 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. Both drugs lower blood pressure by vasodilation, so combined use can cause pronounced hypotension and reflex tachycardia. Risk is greatest with parenteral phentolamine.
How serious is the interaction between Phentolamine 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 and heart rate closely when given together. Reduce doses or space administration if hypotension occurs.
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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