Elvitegravir, cobicistat, emtricitabine, and tenofovir and Sildenafil interaction
Elvitegravir, cobicistat, emtricitabine, and tenofovir and Sildenafil: 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 Elvitegravir, cobicistat, emtricitabine, and tenofovir (Genvoya) label · effective 2025-02-03
John's wort ( Hypericum perforatum ) Lipid-modifying Agents: lomitapide, lovastatin, simvastatin Phosphodiesterase-5 (PDE-5) Inhibitor: sildenafil when administered as REVATIO ® for the treatment of pulmonary arterial hypertension Sedative/hypnotics: triazolam, orally administered midazolam Coadministration of GENVOYA is contraindicated with drugs that: Are highly…
Phosphodiesterase-5 (PDE5) Inhibitors: sildenafil tadalafil vardenafil ↑ PDE5 inhibitors Use of PDE-5 inhibitors for pulmonary arterial hypertension (PAH): Coadministration of sildenafil with GENVOYA is contraindicated when used for treatment of PAH, due to potential for PDE-5 inhibitor associated adverse reactions, including hypotension, syncope, visual disturbances,…
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 in 72 hours, or tadalafil at a single dose not exceeding 10 mg in 72 hours can be used with increased monitoring for PDE-5 inhibitor associated with adverse events.
From the Sildenafil label · effective 2026-07-17
CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, itraconazole, erythromycin) increase SILDENAFIL ORAL FILM exposure.
Erythromycin or strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, saquinavir): Consider a starting dose of 25 mg.
Ritonavir and other CYP3A4 inhibitors Co-administration of ritonavir, a strong CYP3A4 inhibitor, greatly increased the systemic exposure of sildenafil (11-fold increase in AUC).
Co-administration of erythromycin, a moderate CYP3A4 inhibitor, resulted in 160% and 182% increases in sildenafil Cmax and AUC, respectively.
Co-administration of saquinavir, a strong CYP3A4 inhibitor, resulted in 140% and 210% increases in sildenafil Cmax and AUC, respectively.
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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.