Coadministration of rilpivirine (75 mg once daily) and sildenafil (50 mg single dose) decreased rilpivirine Cmax and AUC by 8% and 2%, and increased Cmin by 4%. Sildenafil Cmax and AUC decreased by 7% and 3%; N-desmethyl sildenafil Cmax and AUC decreased by 10% and 8%, respectively. No dose adjustment is needed for either drug. [Note: this interaction study has been performed with a dose higher than the licensed dose for rilpivirine assessing the maximal effect on the co-administered drug. The dosing recommendation is applicable to the licensed dose of rilpivirine 25 mg once daily.]