Drug interactions
Avanafil + Nirmatrelvir / ritonavir
Severity: Major
Avanafil and Nirmatrelvir / ritonavir: major interaction.
Last updated Sources: US FDA label
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
Ritonavir in this combination strongly inhibits CYP3A4 and can markedly raise avanafil levels. This may cause severe hypotension, syncope, visual changes and priapism.
What this interaction means in plain words
Avanafil and Nirmatrelvir / ritonavir 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.
Why it happens
Ritonavir and nirmatrelvir inhibit CYP3A4, greatly reducing avanafil clearance.
What to do
Avoid avanafil during treatment and for several days afterward, as no safe dose is established. Use another PDE5 inhibitor at a labeled reduced dose or defer therapy.
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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References
Other interactions of Avanafil
- Amyl nitrite + Avanafil Contraindicated
- Atazanavir + Avanafil Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Avanafil + Conivaptan Contraindicated
- Avanafil + Darunavir Contraindicated
- Avanafil + Fosamprenavir Contraindicated
Frequently asked questions
Can I take Avanafil with Nirmatrelvir / ritonavir?
MediHelp rates the interaction as major. Avanafil and Nirmatrelvir / ritonavir 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. Ritonavir in this combination strongly inhibits CYP3A4 and can markedly raise avanafil levels. This may cause severe hypotension, syncope, visual changes and priapism.
How serious is the interaction between Avanafil and Nirmatrelvir / ritonavir?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid avanafil during treatment and for several days afterward, as no safe dose is established. Use another PDE5 inhibitor at a labeled reduced dose or defer therapy.
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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