Drug interactions
Isoproterenol + Phenoxybenzamine
Severity: Moderate
Isoproterenol 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 irreversibly blocks alpha-receptors, so isoproterenol's beta-2 vasodilation is unopposed. This can cause marked hypotension with reflex tachycardia.
What this interaction means in plain words
Isoproterenol 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
Alpha-adrenergic blockade leaves beta-2 mediated vasodilation unopposed, producing additive hypotension and reflex tachycardia.
What to do
Monitor blood pressure and heart rate and titrate isoproterenol slowly. Ensure adequate volume status.
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 Isoproterenol
Frequently asked questions
Can I take Isoproterenol with Phenoxybenzamine?
MediHelp rates the interaction as moderate. Isoproterenol 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 irreversibly blocks alpha-receptors, so isoproterenol's beta-2 vasodilation is unopposed. This can cause marked hypotension with reflex tachycardia.
How serious is the interaction between Isoproterenol 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 and titrate isoproterenol slowly. Ensure adequate volume status.
What other medicines interact with Isoproterenol?
MediHelp also lists interactions of Isoproterenol with, for example, Adrenaline-articaine, Bisoprolol, Budesonide-formoterol. The full list is on the Isoproterenol page.
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