Viagra (sildenafil citrate) is a prescription medicine intended for male patients diagnosed with erectile dysfunction that find it impossible to have sex because of insufficient erections. Let your doctor know about pulmonary veno-occlusive disease, high cholesterol, blood circulation problems, diabetes, bleeding disorder, stroke, heart disease, irregular heartbeat, stomach ulcer, kidney disease, blood cell problems, high or low blood pressure, or a recent heart attack. In general, however, Viagra can be taken by most men and will be beneficial for 80% of them no matter what their impotence was caused by. Only a few side effects are commonly reported when Viagra is taken. These include stuffy nose, memory problems, back pain, upset stomach, warmth or redness in your face, or neck, headache and some other symptoms that can be quite individual. It's a good idea to make a list of all the meds you are using at the moment, especially if they include azole antifungals, mibefradil, HIV protease inhibitors, cimetidine, erythromycin, other medications for impotence, alpha-blocker medications, rifamycins, and high blood pressure medicines. Your doctor will be able to prescribe a more accurate dose then.