Itraconazole and Sildenafil interaction
Itraconazole 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 Itraconazole (Tolsura) label · effective 2025-04-23
Aliskiren Riociguat Sildenafil (for pulmonary hypertension) Tadalafil (for pulmonary hypertension) Not recommended during and 2 weeks after TOLSURA treatment.
Dutasteride Oxybutynin Sildenafil (for erectile dysfunction) Tadalafil (for erectile dysfunction and benign prostatic hyperplasia) Tolterodine Monitor for adverse reactions.
For sildenafil and tadalafil, see also Urologic Drugs below.
For sildenafil and tadalafil, see also Cardiovascular Drugs above.
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.
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.