Sildenafil

What is this medicine?

SILDENAFIL relaxes muscles and increases blood flow to particular areas of the body.

Sildenafil is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women. Sildenafil under the brand name Viagra is used to treat erectile dysfunction (impotence) in men. Do not take Viagra while also taking Sildenafil, unless your doctor tells you to.

Sildenafil may also be used for other purposes not listed in this medication guide.

How should I use this medicine?

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 sudden and serious decrease in blood pressure. 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. Do not take Viagra while also taking Sildenafil, unless your doctor tells you to. 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.

What should I tell my health care provider before I take this medicine?

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.

To make sure Sildenafil is safe for you, tell your doctor about your other medical conditions, especially:

• heart disease or heart rhythm problems, coronary artery disease;
• a recent history (in the past 6 months) of a heart attack, stroke, or congestive heart failure;
• high or low blood pressure;
• liver disease;
• kidney disease;
• a blood cell disorder such as sickle cell anemia, multiple myeloma, or leukemia;
• a bleeding disorder such as hemophilia;
• a stomach ulcer;
• retinitis pigmentosa (an inherited condition of the eye);
• a physical deformity of the penis (such as Peyronie's disease); or
• if you have been told you should not have sexual intercourse for health reasons.

If you have any of these conditions, you may need a dose adjustment or special tests to safely take Sildenafil.
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.

FDA pregnancy category B: This medication is not expected to be harmful to an unborn baby. Do not use Sildenafil without telling your doctor if you are pregnant or plan to become pregnant during treatment. It is not known if Sildenafil passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a babe.

How should I take Sildenafil?

Take Sildenafil exactly as it was prescribed for you. Do not take it in larger or smaller doses or for longer than recommended by your doctor. Follow the directions on your prescription label.

Sildenafil is usually taken three times each day, about 4 to 6 hours apart.

Store Sildenafil at room temperature away from moisture and heat.

What happens if I miss a dose?

If you miss a dose of Sildenafil, 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 or call the Poison Help line at 1-800-222-1222. Overdose symptoms may include chest pain, nausea, irregular heartbeat, and feeling light-headed or fainting.

What should I avoid while taking Sildenafil?

Avoid drinking alcohol, which can increase some of the side effects of Sildenafil. Avoid using medicines to treat impotence, such as alprostadil (Caverject, Muse, Edex) or yohimbine (Yocon, Yodoxin, others), without first talking to your doctor.

What may interact with this medicine?

Do not take Sildenafil with similar medications such as avanafil (Stendra), tadalafil (Cialis) or vardenafil (Levitra). Tell your doctor about any medications you use for erectile dysfunction.

Before taking Sildenafil, tell your doctor if you are using any of the following medications:

• bosentan (Tracleer);
• cimetidine (Tagamet, Tagamet HB);
• conivaptan (Vaprisol);
• imatinib (Gleevec);
• isoniazid (for treating tuberculosis);
• an antidepressant such as nefazodone;
• an antibiotic such as clarithromycin (Biaxin), erythromycin (E.E.S., EryPed, Ery-Tab, Erythrocin, Pediazole), rifampin (Rifater, Rifadin, Rifamate), or telithromycin (Ketek);
• antifungal medication such as itraconazole (Sporanox), ketoconazole (Nizoral), or voriconazole (Vfend);
• drugs to treat high blood pressure or a prostate disorder, such as alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), terazosin (Hytrin), silodosin (Rapaflo), tamsulosin (Flomax, Jalyn);
• heart or blood pressure medication such as amlodipine (Norvasc, Caduet, Exforge, Lotrel, Tekamlo, Tribenzor, Twynsta, Amturnide), diltiazem (Cardizem, Cartia, Dilacor, Diltia, Diltzac, Taztia, Tiazac), nicardipine (Cardene), quinidine (Quin-G), or verapamil (Calan, Covera, Isoptin, Verelan);
• the hepatitis C medications boceprevir (Victrelis) or telaprevir (Incivek); or
• HIV/AIDS medicine such as atazanavir (Reyataz), darunavir (Prezista), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Kaletra, Norvir), saquinavir (Fortovase), or tipranavir (Aptivus).

This list is not complete and other drugs may interact with Sildenafil. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

What happens if I miss a dose?

Use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line. Overdose symptoms may include severe forms of some of the side effects listed in this medication guide.

What side effects may I notice from this medicine?

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 Sildenafil side effects may include:

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

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.