Drug interactions
Avanafil + Prazosin
Severity: Major
Avanafil and Prazosin: 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
Combining a PDE5 inhibitor with an alpha-blocker can cause symptomatic postural hypotension, dizziness or syncope. The risk is greatest when starting or increasing doses.
What this interaction means in plain words
Avanafil and Prazosin 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; Prazosin belongs to Genitourinary.
Why it happens
Additive vasodilation from alpha-1 blockade and PDE5 inhibition.
What to do
Start avanafil only when the patient is stable on the alpha-blocker and begin with the lowest dose. Counsel about orthostatic symptoms and monitor blood pressure.
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 Prazosin
- Alfuzosin + Prazosin Major
- Amifostine + Prazosin Major
- Doxazosin + Prazosin Major
- Dutasteride-tamsulosin + Prazosin Major
- Phenoxybenzamine + Prazosin Major
- Prazosin + Sildenafil Major
Frequently asked questions
Can I take Avanafil with Prazosin?
MediHelp rates the interaction as major. Avanafil and Prazosin 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. Combining a PDE5 inhibitor with an alpha-blocker can cause symptomatic postural hypotension, dizziness or syncope. The risk is greatest when starting or increasing doses.
How serious is the interaction between Avanafil and Prazosin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start avanafil only when the patient is stable on the alpha-blocker and begin with the lowest dose. Counsel about orthostatic symptoms and monitor blood pressure.
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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