Avanafil and Darunavir interaction
Avanafil and Darunavir: 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 Darunavir (PREZISTA) label · effective 2025-08-29
Co-administration of PREZISTA/ritonavir and avanafil is not recommended.
John's wort ( Hypericum perforatum ) Hepatitis C direct acting antiviral: elbasvir/grazoprevir Lipid modifying agents: lomitapide, lovastatin, simvastatin Opioid Antagonist: naloxegol PDE-5 inhibitor: sildenafil when used for treatment of pulmonary arterial hypertension Sedatives/hypnotics: orally administered midazolam, triazolam Co-administration of PREZISTA/ritonavir…
Use of PDE-5 inhibitors for pulmonary arterial hypertension (PAH): Co-administration with sildenafil used for PAH is contraindicated due to potential for sildenafil associated adverse reactions (which include visual disturbances, hypotension, prolonged erection, and syncope).
PDE-5 inhibitors : e.g. avanafil, sildenafil, tadalafil, vardenafil ↑ PDE-5 inhibitors (only the use of sildenafil at doses used for treatment of erectile dysfunction has been studied with PREZISTA/ritonavir) Co-administration with PREZISTA/ritonavir may result in an increase in PDE-5 inhibitor-associated adverse events, including hypotension, syncope, visual…
Use of PDE-5 inhibitors for erectile dysfunction: Sildenafil at a single dose not exceeding 25 mg in 48 hours, vardenafil at a single dose not exceeding 2.5 mg dose in 72 hours, or tadalafil at a single dose not exceeding 10 mg dose in 72 hours can be used with increased monitoring for PDE-5 inhibitor-associated adverse events.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.