Levitra is used to treat adult men with erectile dysfunction (sometimes called impotence), when they cannot get or keep a hard penis (erection) sufficient for satisfactory sexual activity. For Levitra to be effective, sexual stimulation is required. Levitra (vardenafil) belongs to a class of medications called phosphodiesterase (PDE) inhibitors. Vardenafil relaxes muscles found in the walls of blood vessels and increases blood flow to particular areas of the body.