Drug interactions
Captopril-hydrochlorothiazide + Doxazosin
Severity: Moderate
Captopril-hydrochlorothiazide and Doxazosin: 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
Doxazosin is an alpha-blocker that can cause marked first-dose orthostatic hypotension, and the effect is increased with ACE inhibitors and diuretics. Dizziness, syncope and falls may occur.
What this interaction means in plain words
Captopril-hydrochlorothiazide and Doxazosin 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-hydrochlorothiazide belongs to Cardiovascular; Doxazosin belongs to Genitourinary.
Why it happens
Additive vasodilation and hypotension from alpha-1 blockade, ACE inhibition and diuresis.
What to do
Start doxazosin at a low dose at bedtime and monitor blood pressure; consider temporarily reducing the diuretic dose.
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-hydrochlorothiazide
- Aliskiren + Captopril-hydrochlorothiazide Contraindicated
- Captopril-hydrochlorothiazide + Dofetilide Contraindicated
- Captopril-hydrochlorothiazide + Sacubitril / valsartan Contraindicated
- Aceclofenac + Captopril-hydrochlorothiazide Major
- Aldesleukin + Captopril-hydrochlorothiazide Major
- Amifostine + Captopril-hydrochlorothiazide Major
Other interactions of Doxazosin
- Alfuzosin + Doxazosin Major
- Amifostine + Doxazosin Major
- Avanafil + Doxazosin Major
- Doxazosin + Dutasteride-tamsulosin Major
- Doxazosin + Phentolamine Major
- Doxazosin + Prazosin Major
Frequently asked questions
Can I take Captopril-hydrochlorothiazide with Doxazosin?
MediHelp rates the interaction as moderate. Captopril-hydrochlorothiazide and Doxazosin 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. Doxazosin is an alpha-blocker that can cause marked first-dose orthostatic hypotension, and the effect is increased with ACE inhibitors and diuretics. Dizziness, syncope and falls may occur.
How serious is the interaction between Captopril-hydrochlorothiazide and Doxazosin?
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 doxazosin at a low dose at bedtime and monitor blood pressure; consider temporarily reducing the diuretic dose.
What other medicines interact with Captopril-hydrochlorothiazide?
MediHelp also lists interactions of Captopril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Sacubitril / valsartan. The full list is on the Captopril-hydrochlorothiazide page.
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