Viagra

Generic Name: sildenafil (sil DEN uh fil)

Brand name: Viagra, Revatio

Drug interactions:

sildenafil (viagra) increases the effects of the blood pressure lowering medications. It also increases the blood pressure lowering effects of nitrates, e.g. isosorbide dinitrate (Isordil), isosorbide mononitrate (Imdur, Ismo, Monoket), nitroglycerin (Nitro-Dur, Transderm-Nitro) that are used primarily for treating angina. Patients taking nitrates should not receive sildenafil (viagra).
Cimetidine (Tagamet), erythromycin, ketoconazole (Nizoral), itraconazole (Sporanox) and mibefradil (Posicor) can cause marked increases in the amount of sildenafil (viagra) in the body. Patients taking these medications should be observed carefully if sildenafil (viagra) is used.
It is expected that rifampin will decrease blood levels of sildenafil (viagra) and probably reduce its effectiveness.

The most important information you should know about Viagra:

Do not take viagra if you are also using a nitrate drug for chest pain or heart problems. This includes nitroglycerin (Nitrostat, Nitrolingual, Nitro-Dur, Nitro-Bid, and others), isosorbide dinitrate (Dilatrate-SR, Isordil, Sorbitrate), and isosorbide mononitrate (Imdur, ISMO, Monoket). Nitrates are also found in some recreational drugs such as amyl nitrate or nitrite ("poppers"). Taking viagra with a nitrate medicine can cause a serious decrease in blood pressure, leading to fainting, stroke, or heart attack.

If you become dizzy or nauseated, or have pain, numbness, or tingling in your chest, arms, neck, or jaw during sexual activity, stop and call your doctor right away. You could be having a serious side effect of viagra.

Do not take viagra more than once a day. Allow 24 hours to pass between doses.

Contact your doctor or seek emergency medical attention if your erection is painful or lasts longer than 4 hours. A prolonged erection (priapism) can damage the penis.

A small number of patients have had a sudden loss of eyesight after taking viagra. This type of vision loss is caused by decreased blood flow to the optic nerve of the eye. It is not clear whether viagra is the actual cause of such vision loss. Sudden vision loss with viagra use has occurred most often in people with heart disease, diabetes, high blood pressure, high cholesterol, or certain pre-existing eye problems, and in those who smoke or are over 50 years old.

Stop using viagra and get emergency medical help if you have sudden vision loss.