This helps blood flow into your penis more easily, and helps you get firmer erections that last for longer. The following information includes only the average doses of this medicine. If you take too much sildenafil or take it together with these medicines, the chance for side effects will be higher. Follow your doctor’s orders or the directions on the label. Keep from freezing.Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in men. It is also used to treat pulmonary arterial hypertension, a serious heart and lung Missing: usa.  · Viagra; Descriptions. Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where . Viagra (sildenafil) is a prescription drug that’s used to treat erectile dysfunction (ED). The drug comes as a tablet you’ll take by swallowing. It’s usually taken as needed about 1 hour.