Drug interactions
Penbutolol + Phentolamine
Severity: Moderate
Penbutolol and Phentolamine: 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, so concurrent use may cause additive hypotension. Beta-blockade may also blunt the reflex tachycardia from phentolamine.
What this interaction means in plain words
Penbutolol and Phentolamine 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.
Why it happens
Additive pharmacodynamic blood pressure lowering through alpha-blockade and beta-blockade.
What to do
Monitor blood pressure and heart rate when starting or adjusting either drug. Reduce the dose if symptomatic 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 Phentolamine
Frequently asked questions
Can I take Penbutolol with Phentolamine?
MediHelp rates the interaction as moderate. Penbutolol and Phentolamine 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, so concurrent use may cause additive hypotension. Beta-blockade may also blunt the reflex tachycardia from phentolamine.
How serious is the interaction between Penbutolol and Phentolamine?
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 when starting or adjusting either drug. Reduce the dose if symptomatic hypotension occurs.
What other medicines interact with Phentolamine?
MediHelp also lists interactions of Phentolamine with, for example, Alfuzosin, Avanafil, Doxazosin. The full list is on the Phentolamine page.
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