Avanafil and Ritonavir interaction
Avanafil and Ritonavir: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Avanafil label · effective 2025-12-17
Do not use avanafil in patients taking ritonavir.
Do not use avanafil in patients taking strong CYP3A4 inhibitors [see Warnings and Precautions ( 5.2 ) and Dosage and Administration ( 2.3 )].
Inhibitors of CYP3A4 may reduce avanafil clearance and increase plasma concentrations of avanafil.
For patients taking concomitant moderate CYP3A4 inhibitors (including erythromycin, amprenavir, aprepitant, diltiazem, fluconazole, fosamprenavir, and verapamil), the maximum recommended dose of avanafil is 50 mg, not to exceed once every 24 hours [see Drug Interactions ( 7.2 )].
• CYP3A4 inhibitors (e.g., ketoconazole, ritonavir, erythromycin) increase avanafil exposure ( 7.2 )
From the Ritonavir (Norvir) label · effective 2026-07-23
Do not use ritonavir with avanafil because a safe and effective avanafil dosage regimen has not been established.
…lovastatin, simvastatin ○ Microsomal triglyceride transfer protein (MTTP) Inhibitor: lomitapide ○ Non-opioid Analgesic (selective blocker of Na v 1.8 sodium channels): suzetrigine ○ PDE5 Inhibitor: sildenafil (Revatio ® ) when used for the treatment of pulmonary arterial hypertension ○ Sedative/Hypnotics: triazolam, orally administered midazolam • NORVIR is contraindicated…
Use of PDE5 inhibitors for pulmonary arterial hypertension (PAH): Sildenafil (Revatio ® ) is contraindicated [see Contraindications ( 4 ) ] .
PDE5 Inhibitors: avanafil sildenafil, tadalafil, vardenafil ↑ avanafil ↑ sildenafil ↑ tadalafil ↑ vardenafil Sildenafil when used for the treatment of pulmonary arterial hypertension (Revatio ® ) is contraindicated due to the potential for sildenafil-associated adverse events, including visual abnormalities, hypotension, prolonged erection, and syncope [see Contraindications…
Coadministration of ritonavir with these drugs may result in an increase in PDE5 inhibitor associated adverse events, including hypotension, syncope, visual changes, and prolonged erection.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.