Avanafil and Clarithromycin interaction
Avanafil and Clarithromycin: 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 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 )
Studies have shown that drugs that inhibit CYP3A4 can increase avanafil exposure.
From the Clarithromycin label · effective 2026-01-01
Co-administration of these phosphodiesterase inhibitors with clarithromycin is not recommended.
Phosphodiesterase inhibitors: Sildenafil Tadalafil Vardenafil Use With Caution Sildenafil, Tadalafil, Vardenafil: Each of these phosphodiesterase inhibitors is primarily metabolized by CYP3A, and CYP3A will be inhibited by concomitant administration of clarithromycin.
Co-administration of clarithromycin with sildenafil, tadalafil, or vardenafil will result in increased exposure of these phosphodiesterase inhibitors.
Increased systemic exposure of these drugs may occur with clarithromycin; reduction of dosage for phosphodiesterase inhibitors should be considered (see their respective prescribing information).
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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.