Sildenafil is used to treat male sexual function problems (impotence orerectile dysfunction-ED). In combination with sexual stimulation, sildenafil works by increasingbloodflow to thepenisto help a man get and keep an erection Sildenafil belongs to a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions. Sildenafil...