How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup. Sildenafil treats PAH by relaxing the blood vessels in the lungs to allow blood to flow easily. These include a heart attack, stroke or a serious heart rhythm disorder in the past six months. To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and site usage information with other information we have about you. Sildenafil Viagra is used to treat erectile dysfunction impotence; inability to get or keep an erection in men.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 . Drug Images What is Viagra? If you have erectile dysfunction (ED), your doctor may recommend that you take Viagra. It’s a prescription drug that’s used in adult . Sildenafil oral tablet is available as the brand-name drugs Viagra and Revatio. It’s also available as a generic drug. Generic drugs usually cost less than the .