Some medications should not be taken with sildenafil. These include itraconazole Sporanox, Tolsura , ketoconazole Extina, Ketozole, others and ritonavir Norvir. This development was credited largely “due to the introduction of generic products. Before starting, stopping, or changing any medications while taking sildenafil, please get the advice of your doctor or pharmacist. They’re often the first line of treatment for trouble getting or keeping an erection, called erectile dysfunction ED.Sildenafil, sold under the brand name Viagra, among others, is a medication used to treat erectile dysfunction and pulmonary arterial hypertension. [4] [8] It is also sometimes used . Interactions. 1. How it works. Sildenafil may be used to treat erectile dysfunction (ED or impotence) in men (Viagra brand) or pulmonary arterial hypertension in both men and . Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in adults (Liqrev, Revatio) and children 1 year of age and older (Revatio) with pulmonary arterial .