Ask your healthcare professional how you should dispose of any medicine you do not use. A single dose, or a hit, will be less expensive than buying a bottle of pills, buying by gram, or buying by ounce—depending on the type of drug and the typical dosage. John’s wort. Children 1 year of age and older weighing 20 to 45 kg—20 mg 3 times a day. Side Effects Along with its needed effects, a medicine may cause some unwanted effects. 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.According to an article by the New York Post, the average cost of a mg Viagra pill is $40 at most U.S. pharmacies. The degree of variation from one pharmacy to another is marked by a few dollars. In the above table, the lowest price for a day supply of mg pills is $ at Walmart. At the other end of the scale Rite Aid members.  · Compare prices. Drug prices vary by pharmacy. Use GoodRx to find current prices and discounts. Get free coupons. GoodRx coupons can help you pay less than the cash price for your prescription. Show to your pharmacist. It’s easy. Just bring your free coupon to the pharmacy when picking up your prescription. Get sildenafil for as low as $, which is 99% off the average retail price of $ for the most common version, by using a GoodRx coupon. Prices Medicare Drug Info Side Effects Images Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in men.