Drug interactions
Doxazosin + Quinapril
Severity: Moderate
Doxazosin and Quinapril: 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
Combining an alpha-blocker with an ACE inhibitor lowers blood pressure further than either drug alone. Postural hypotension and first-dose syncope are more likely when either agent is started or the dose is raised.
What this interaction means in plain words
Doxazosin and Quinapril 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 through alpha-1 blockade-mediated vasodilation and ACE inhibition-mediated reduction of angiotensin II.
What to do
Start the new drug at a low dose, ideally at bedtime, and monitor blood pressure including standing readings. Reduce the dose of either agent if symptomatic hypotension develops.
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 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 Doxazosin with Quinapril?
MediHelp rates the interaction as moderate. Doxazosin and Quinapril 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. Combining an alpha-blocker with an ACE inhibitor lowers blood pressure further than either drug alone. Postural hypotension and first-dose syncope are more likely when either agent is started or the dose is raised.
How serious is the interaction between Doxazosin and Quinapril?
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 the new drug at a low dose, ideally at bedtime, and monitor blood pressure including standing readings. Reduce the dose of either agent if symptomatic hypotension develops.
What other medicines interact with Doxazosin?
MediHelp also lists interactions of Doxazosin with, for example, Alfuzosin, Amifostine, Avanafil. The full list is on the Doxazosin page.
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