Warnings/Precautions

Viagra is not recommended if you are taking 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, Sorbitrate, Isordil), and isosorbide mononitrate (MonoketImdur, ISMO), or recreational drugs such as amyl nitrate or nitrite ("poppers").

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

* Bosentan (Tracleer);
* Blood thinner such as warfarin (Coumadin);
* Cimetidine (Tagamet, Tagamet HB);
* An antibiotic, for instance, erythromycin (E-Mycin, Eryc, Ery-Tab) or clarithromycin (Biaxin);
* Doxazosin (Cardura), prazosin (Minipress), Terazosin (Hytrin);
* HIV medications 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 like itraconazole (Sporanox) or ketoconazole (Nizoral);
* Carbamazepine (Tegretol), phenobarbital (Luminal), or phenytoin (Dilantin); or
* Rifampin (Rifadin, Rimactane) or rifabutin (Mycobutin).

Notify your doctor about all the former and over-the-counter medications you intake. This includes vitamins, minerals, herbal products, and drugs recommended/prescribed by other doctors. Do not begin taking a new medication without speaking to your doctor.

If you have heart problems critical enough to make sexual activity a risk, you should not use Viagra. Use it carefully, if you've had a heart attack, stroke, or life-threatening heart abnormalities within the past 6 months. Be equally careful, if you have high or low blood pressure, heart failure, or unpredictable angina.

In case you develop any cardiac irregularities (for example, dizziness, nausea, and chest pain) during sexual activity, it is recommended to cease. Tell your doctor about the difficulty as soon as possible.

If you have a state that might result in long-lasting erections, such as sickle cell anemia, multiple myeloma (a condition of the bone marrow), or leukemia, use Viagra with care. Also, use cautiously if you have a genital problem or disfigurement such as Peyronies disease. If an erection persists more than 4 hours, go for a doctor's consultation promptly. In the case of negligence, lasting damage and inability could result.

If you have any kind of bleeding disorder, a stomach ulcer, or the genetical eye condition known as retinitis pigmentosa, use Viagra with caution. The product's safety under these conditions has not been investigated yet.