Generic Name: Sildenafil Tablets 50 mg, 100 mg (sil-DEN-a-fil)
Brand Name: Viagra

What is Viagra?
Viagra relaxes muscles and increases blood flow to particular areas of the body.
Viagra under the name Viagra is used to treat erectile dysfunction (impotence) in men. Another brand of sildenafil is Revatio, which is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women.
Viagra may also be used for other purposes not listed in this medication guide.

What is the most important information I should know about sildenafil?
Do not take sildenafil 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 sildenafil with a nitrate medicine can cause a serious decrease in blood pressure, leading to fainting, stroke, or heart attack. During sexual activity, if you become dizzy or nauseated, or have pain, numbness, or tingling in your chest, arms, neck, or jaw, stop and call your doctor right away. You could be having a serious side effect of sildenafil. Do not take sildenafil 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.
Sildenafil can decrease blood flow to the optic nerve of the eye, causing sudden vision loss. This has occurred in a small number of people taking sildenafil, most of whom also had 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. It is not clear whether sildenafil is the actual cause of vision loss.
Stop using sildenafil and get emergency medical help if you have sudden vision loss.

How should I take sildenafil?
Take sildenafil exactly as it was prescribed for you. Do not take it in larger doses or for longer than recommended by your doctor. Follow the directions on your prescription label.
Revatio is usually taken three times each day, about 4 to 6 hours apart.
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.
Viagra can help you have an erection when sexual stimulation occurs. An erection will not occur just by taking a pill. Follow your doctor's instructions.
During sexual activity, if you become dizzy or nauseated, or have pain, numbness, or tingling in your chest, arms, neck, or jaw, stop and call your doctor right away. You could be having a serious side effect of sildenafil. Store this medication at room temperature away from moisture and heat.

What happens if I miss a dose?
Viagra is used as needed, so you are not likely to be on a dosing schedule.
If you miss a dose of Revatio, take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose?
Seek emergency medical attention if you think you have used too much of this medicine. Overdose symptoms may include chest pain, nausea, irregular heartbeat, and feeling light-headed or fainting.

Sildenafil side effects
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. During sexual activity, if you become dizzy or nauseated, or have pain, numbness, or tingling in your chest, arms, neck, or jaw, stop and call your doctor right away. You could be having a serious side effect of sildenafil.
Stop using sildenafil and call your doctor at once if you have any of these serious side effects:

• sudden vision loss;
• ringing in your ears, or sudden hearing loss;
• chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling;
• irregular heartbeat;
• swelling in your hands, ankles, or feet;
• shortness of breath;
• vision changes;
• feeling light-headed, fainting; or
• penis erection that is painful or lasts 4 hours or longer.

Less serious side effects may include:

• warmth or redness in your face, neck, or chest;
• stuffy nose;
• headache;
• upset stomach; or
• back pain.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

Where can I get more information?
Your pharmacist can provide more information about sildenafil.