Viagra (Sildenafil)

Viagra is used for treating erectile dysfunction (e.g. male impotence). It works by helping the blood flow into the penis to achieve and maintain an erection during sexual stimulation.

Viagra is to be taken 30 minutes to 1 hour before sexual activity. You may take it up to 4 hours before sexual activity. Viagra is not supposed to be taken more often than once per day.

If you are older than 65 years, you can suffer Viagra side effects. However, your physician may prescribe you a lower dose of this medication.

Do not take Viagra, if you are also using a nitrate drug for chest pain or heart problems, including nitroglycerin (Nitrostat, Nitrolingual, Nitro-Dur, Nitro-Bid, Minitran, Deponit, Transderm-Nitro), isosorbide dinitrate (Dilatrate-SR, Isordil, Sorbitrate), and isosorbide mononitrate (Imdur, ISMO, Monoket), or recreational drugs such as amyl nitrate or nitrite ("poppers").

Before taking Viagra, tell your doctor about all other medications you use for erectile dysfunction, or if you are using any of the following medications:

• bosentan (Tracleer);
• a blood thinner such as warfarin (Coumadin);
• cimetidine (Tagamet, Tagamet HB);
• an antibiotic such as erythromycin (E-Mycin, Eryc, Ery-Tab) or clarithromycin (Biaxin);
• doxazosin (Cardura), prazosin (Minipress), Terazosin (Hytrin);
• HIV medicines such as amprenavir (Agenerase), tipranavir (Aptivus), darunavir (Prezista), efavirenz (Sustiva), nevirapine (Viramune), indinavir (Crixivan), saquinavir (Invirase, Fortovase), lopinavir/ritonavir (Kaletra), fosamprenavir (Lexiva), ritonavir (Norvir), atazanavir (Reyataz), or nelfinavir (Viracept);
• an antifungal medication such as itraconazole (Sporanox) or ketoconazole (Nizoral);
• carbamazepine (Tegretol), phenobarbital (Luminal), or phenytoin (Dilantin); or
• rifampin (Rifadin, Rimactane) or rifabutin (Mycobutin).

Frequently asked questions about Viagra

If you experience any of the following serious side effects, stop taking Viagra and seek emergency medical attention or notify your doctor immediately:

• 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.

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