Drug interactions
Bisoprolol + Phenoxybenzamine
Severity: Moderate
Bisoprolol and Phenoxybenzamine: 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
Phenoxybenzamine causes long-lasting alpha blockade and vasodilation, and adding bisoprolol increases the risk of hypotension. In pheochromocytoma this combination is intentional, but beta-blockers should only follow adequate alpha blockade to avoid hypertensive crisis.
What this interaction means in plain words
Bisoprolol and Phenoxybenzamine 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 hypotensive effects from alpha-adrenergic and beta-adrenergic blockade.
What to do
Monitor blood pressure and heart rate; in pheochromocytoma start the beta-blocker only after established alpha blockade. Adjust doses for orthostatic hypotension.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Bisoprolol and Phenoxybenzamine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Bisoprolol
Frequently asked questions
Can I take Bisoprolol with Phenoxybenzamine?
MediHelp rates the interaction as moderate. Bisoprolol and Phenoxybenzamine 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. Phenoxybenzamine causes long-lasting alpha blockade and vasodilation, and adding bisoprolol increases the risk of hypotension. In pheochromocytoma this combination is intentional, but beta-blockers should only follow adequate alpha blockade to avoid hypertensive crisis.
How serious is the interaction between Bisoprolol and Phenoxybenzamine?
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; in pheochromocytoma start the beta-blocker only after established alpha blockade. Adjust doses for orthostatic hypotension.
What other medicines interact with Bisoprolol?
MediHelp also lists interactions of Bisoprolol with, for example, Aldesleukin, Amifostine, Amiodarone. The full list is on the Bisoprolol page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
