Drug interactions
Nirmatrelvir / ritonavir + Tadalafil
Severity: Major
Nirmatrelvir / ritonavir and Tadalafil: 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
Ritonavir in this combination strongly inhibits CYP3A4 and raises tadalafil exposure. This increases the risk of hypotension, syncope, visual changes and priapism.
What this interaction means in plain words
Nirmatrelvir / ritonavir and Tadalafil 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, reducing tadalafil clearance.
What to do
Avoid for pulmonary hypertension, or follow labeling on holding and reintroducing tadalafil. For erectile dysfunction, hold or reduce tadalafil to the labeled low dose during treatment and for a few days after.
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 Tadalafil
- Amyl nitrite + Tadalafil Contraindicated
- Isosorbide dinitrate + Tadalafil Contraindicated
- Isosorbide mononitrate + Tadalafil Contraindicated
- Nitroglycerin po + Tadalafil Contraindicated
- Nitroglycerin rectal + Tadalafil Contraindicated
- Nitroglycerin sublingual + Tadalafil Contraindicated
Frequently asked questions
Can I take Nirmatrelvir / ritonavir with Tadalafil?
MediHelp rates the interaction as major. Nirmatrelvir / ritonavir and Tadalafil 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 raises tadalafil exposure. This increases the risk of hypotension, syncope, visual changes and priapism.
How serious is the interaction between Nirmatrelvir / ritonavir and Tadalafil?
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 for pulmonary hypertension, or follow labeling on holding and reintroducing tadalafil. For erectile dysfunction, hold or reduce tadalafil to the labeled low dose during treatment and for a few days after.
What other medicines interact with Tadalafil?
MediHelp also lists interactions of Tadalafil with, for example, Amyl nitrite, Isosorbide dinitrate, Isosorbide mononitrate. The full list is on the Tadalafil page.
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