Sildenafil, or Viagra, is excreted as metabolites from the body in feces and urine. Yes, a small percentage of the study group experienced headaches, nausea, facial flushing, diarrhea, urinary tract infection and visual changes to color sensitivity. The main contraindication to prescribing Viagra are people who suffer from a rare disease, retinitis pigmentosa, or those who are on nitroglycerin or nitrous oxide. Recently, it has been reported that 16 Viagra patients have died. While there is no direct evidence that Viagra caused the deaths, readers should be aware that sexual activity increases cardiac risk.
Male impotence is often a side effect of more serious cardiovascular problems.
Viagra MUST NOT be taken by persons who are on medications containing nitrates, such as nitroglycerine tablets, as this could lead to dangerous lowering of blood pressure. There is evidence to suggest that Viagra may interact with other medications in such a way as to increase health risk. Men who have medical conditions, such as sickle cell anemia, leukemia, or multiple myeloma, or those with abnormally-shaped penis should also not take Viagra because of a possibility of producing a sustained erection. No, Viagra should only be taken by prescription from a qualified physician. You must tell your doctor exactly what other medications you are taking.