Viagra contains sildenafil which is a prescription medicine used to treat the symptoms of erectile dysfunction. Viagra may be used alone or with other medications. Viagra belongs to a class of drugs called PAH, PDE-5 Inhibitors, Phosphodiesterase-5 Enzyme Inhibitors. Viagra relaxes muscles found in the walls of blood vessels and increases blood flow to particular areas of the body. Viagra is used to treat erectile dysfunction (impotence) in men.
Dose and Administration: Take Viagra exactly as it was prescribed for you. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended. Viagra is usually taken only when needed, 30 minutes to 1 hour before sexual activity. You may take it up to 4 hours before sexual activity. Do not take Viagra more than once per day.
Cautions: Do not take Viagra if you are also using a nitrate drug for chest pain or heart problems. This includes nitroglycerin, isosorbide dinitrate, and isosorbide mononitrate. Viagra should be use with caution in patients who have conditions which may predispose them to priapism (such as sickle cell anemia, multiple myeloma, or leukemia).