Levitra, also known as Vardenafil, is a medicine that is used to treat erectile dysfunction (ED), which is the inability to get or maintain an erection. The causes of ED are varied but can include medical conditions, such as diabetes, hormonal problems and psychological conditions such as stress and depression. It can also be a side effect of certain medications. Vardenafil belongs to a class of drugs known as PDE5 inhibitors and it works by relaxing the muscles and increasing the flow of blood to the penis. It may also be effective in the treatment of premature ejaculation, which is where ejaculation occurs too quickly during sexual intercourse.