Drug interactions
Avanafil + Doxazosin
Severity: Major
Avanafil and Doxazosin: major 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
Both agents lower blood pressure, and combining a PDE5 inhibitor with an alpha-blocker can cause symptomatic postural hypotension, dizziness or syncope. The risk is greatest when treatment is started or doses are increased.
What this interaction means in plain words
Avanafil and Doxazosin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Avanafil belongs to Genitourinary; Doxazosin belongs to Genitourinary.
Why it happens
Additive vasodilation from PDE5 inhibition and alpha-1 adrenergic blockade.
What to do
Ensure the patient is stable on doxazosin before starting avanafil at the lowest dose. Monitor for orthostatic hypotension and counsel the patient to rise slowly.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Avanafil
- Amyl nitrite + Avanafil Contraindicated
- Atazanavir + Avanafil Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Avanafil + Conivaptan Contraindicated
- Avanafil + Darunavir Contraindicated
- Avanafil + Fosamprenavir Contraindicated
Other interactions of Doxazosin
- Alfuzosin + Doxazosin Major
- Amifostine + Doxazosin Major
- Doxazosin + Dutasteride-tamsulosin Major
- Doxazosin + Phentolamine Major
- Doxazosin + Prazosin Major
- Doxazosin + Sildenafil Major
Frequently asked questions
Can I take Avanafil with Doxazosin?
MediHelp rates the interaction as major. Avanafil and Doxazosin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both agents lower blood pressure, and combining a PDE5 inhibitor with an alpha-blocker can cause symptomatic postural hypotension, dizziness or syncope. The risk is greatest when treatment is started or doses are increased.
How serious is the interaction between Avanafil and Doxazosin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Ensure the patient is stable on doxazosin before starting avanafil at the lowest dose. Monitor for orthostatic hypotension and counsel the patient to rise slowly.
What other medicines interact with Avanafil?
MediHelp also lists interactions of Avanafil with, for example, Amyl nitrite, Atazanavir, Clarithromycin. The full list is on the Avanafil page.
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