Vardenafil is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Vardenafil is in a class of medications called phosphodiesterase (PDE) inhibitors. It works by increasing blood flow to the penis during sexual stimulation. This increased blood flow can cause an erection. Vardenafil does not cure erectile dysfunction or increase sexual desire. Vardenafil does not prevent pregnancy or the spread of sexually transmitted diseases such as human immunodeficiency virus (HIV).