People are sometimes prescribed Viagra (sildenafil citrate) for the treatment of erectile dysfunction that can be also referred to as male impotence. Make sure you always take Viagra as prescribed. If you did not visit a doctor to get a prescription, and decided to do this online instead, make sure you read the label carefully. You will need to keep in mind that such conditions as blood system cancers, coronary artery disease, sickle cell anemia, very high or low blood pressure, eye problems, liver disease, active stomach ulcers, penis conditions, kidney disease, recent stroke, heart failure, recent heart attack, or any bleeding disorders, may require a dose adjustment for you to benefit from the treatment. You will also be supposed to avoid taking such drugs as HIV protease inhibitors, other medications for impotence, cimetidine, azole antifungals, alpha-blocker medications, high blood pressure medicines, erythromycin, mibefradil, or rifamycins, as they have been reported to interact with Viagra. The effects of Viagra are based on increasing the blood flow in the tissues of the penis making it possible for you to get an erection hard enough to have sex, generic Viagra working in the same way as brand name Viagra.