Drug interactions
Phenoxybenzamine + Phentolamine
Severity: Moderate
Phenoxybenzamine 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 are alpha-adrenergic blockers, so combined use can cause profound hypotension, reflex tachycardia and dizziness. The combination offers little added benefit.
What this interaction means in plain words
Phenoxybenzamine 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 alpha-adrenergic receptor blockade.
What to do
Avoid routine combination. If both are used, for example in pheochromocytoma care, monitor blood pressure and heart rate closely and adjust doses.
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 Phenoxybenzamine with Phentolamine?
MediHelp rates the interaction as moderate. Phenoxybenzamine 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 are alpha-adrenergic blockers, so combined use can cause profound hypotension, reflex tachycardia and dizziness. The combination offers little added benefit.
How serious is the interaction between Phenoxybenzamine 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: Avoid routine combination. If both are used, for example in pheochromocytoma care, monitor blood pressure and heart rate closely and adjust doses.
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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