Drug interactions
Captopril + Prazosin
Severity: Moderate
Captopril and Prazosin: 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
Prazosin can cause a marked first-dose hypotensive response, which may be amplified in patients taking captopril. Syncope and dizziness are the main risks.
What this interaction means in plain words
Captopril and Prazosin 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.
Captopril belongs to Cardiovascular; Prazosin belongs to Genitourinary.
Why it happens
Additive vasodilation from alpha-1 blockade and ACE inhibition.
What to do
Start prazosin at a low dose at bedtime and monitor blood pressure after the first dose and each titration. Consider temporarily lowering the captopril dose when starting prazosin.
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
Other interactions of Prazosin
- Alfuzosin + Prazosin Major
- Amifostine + Prazosin Major
- Avanafil + Prazosin Major
- Doxazosin + Prazosin Major
- Dutasteride-tamsulosin + Prazosin Major
- Phenoxybenzamine + Prazosin Major
Frequently asked questions
Can I take Captopril with Prazosin?
MediHelp rates the interaction as moderate. Captopril and Prazosin 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. Prazosin can cause a marked first-dose hypotensive response, which may be amplified in patients taking captopril. Syncope and dizziness are the main risks.
How serious is the interaction between Captopril and Prazosin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start prazosin at a low dose at bedtime and monitor blood pressure after the first dose and each titration. Consider temporarily lowering the captopril dose when starting prazosin.
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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