Adults 65 years of age and older—25 mg as a single dose no more than once a day, 1 hour before sexual intercourse. Make sure you have discussed any other medications you are currently taking or plan to take before starting sildenafil with your doctor and pharmacist. Often, these are prescribed for chest pain called angina. Also tell your doctor if you have or have ever had pulmonary veno-occlusive disease PVOD; blockage of veins in the lungs ; a stomach ulcer; heart, kidney, or liver disease; a heart attack; heart failure; angina chest pain ; an irregular heartbeat; a stroke; chest pain; high or low blood pressure; high cholesterol; a bleeding disorder; blood circulation problems; blood cell problems such as sickle cell anemia a disease of the red blood cells , multiple myeloma cancer of the plasma cells , or leukemia cancer of the white blood cells ; conditions affecting the shape of the penis e. Sildenafil Viagra is used to treat erectile dysfunction impotence; inability to get or keep an erection in men. Sildenafil does not prevent pregnancy or the spread of sexually transmitted diseases such as human immunodeficiency virus HIV.Viagra (sildenafil) is a brand-name oral tablet prescribed for erectile dysfunction. The cost of the drug with and without insurance can depend on several factors, such as whether . Compare prices and print coupons for Tadalafil (Cialis) (Generic Cialis) and other drugs at CVS, Walgreens, and other pharmacies. Prices start at $ How much does Tadalafil (Cialis) cost? expand_more. The lowest GoodRx price for the most common version of Tadalafil (Cialis) is around $, 96% off the average retail price of $  · What is the cost of sildenafil without insurance? The cost of sildenafil without insurance starts at $* for a quantity of 30, 20mg tablets, using a RxSaver coupon. The cost of sildenafil can vary in price depending on the pharmacy your sildenafil prescription is filled at. Below is a list of pharmacies and the starting cost of a sildenafil.