Drug interactions
Captopril + Phenoxybenzamine
Severity: Moderate
Captopril 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 marked vasodilation. With captopril, hypotension and orthostatic symptoms may be exaggerated, especially at the start of treatment.
What this interaction means in plain words
Captopril 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 vasodilation from irreversible alpha-adrenergic blockade and ACE inhibition.
What to do
Introduce each drug at a low dose and titrate gradually while monitoring supine and standing blood pressure.
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 Captopril
- Aliskiren + Captopril Contraindicated
- Captopril + Sacubitril / valsartan Contraindicated
- Captopril + Sacubitril-valsartan Contraindicated
- Amifostine + Captopril Major
- Amiloride + Captopril Major
- Amlodipine-hydrochlorothiazide-valsartan + Captopril Major
Frequently asked questions
Can I take Captopril with Phenoxybenzamine?
MediHelp rates the interaction as moderate. Captopril 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 marked vasodilation. With captopril, hypotension and orthostatic symptoms may be exaggerated, especially at the start of treatment.
How serious is the interaction between Captopril 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: Introduce each drug at a low dose and titrate gradually while monitoring supine and standing blood pressure.
What other medicines interact with Captopril?
MediHelp also lists interactions of Captopril with, for example, Aliskiren, Sacubitril / valsartan, Sacubitril-valsartan. The full list is on the Captopril page.
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