Alpha-blockers are sometimes prescribed for prostate problems or high blood pressure. Viagra can also cause health problems for people with certain medical conditions, like high blood pressure, cardiovascular disease , heart failure, previous heart attacks, leukemia, multiple myeloma and sickle cell anemia. Protein binding is independent of total drug concentrations. Although the interaction between other protease inhibitors and sildenafil has not been studied, their concomitant use is expected to increase sildenafil levels. How should this medicine be used? Do not stop taking sildenafil without talking to your doctor. Do not mix the liquid with other medications or add anything to flavor the medication.Examples of Viagra’s more commonly reported side effects include: headache. flushing (temporary warmth, redness, or deepening of skin color) stuffy nose. indigestion (upset stomach) mild vision. Still, if your doctor says it’s okay for you to use and you end up paying out-of-pocket, you can still get the generic for a lot less than Viagra. According to price-comparison site test1.ru Sildenafil citrate is a white to off-white crystalline powder with a solubility of mg/mL in water and a molecular weight of VIAGRA is formulated as blue, film-coated rounded-diamond-shaped tablets equivalent to 25 mg, 50 mg and mg of sildenafil for oral administration.