To find out how the cost of Viagra or Revatio compares with the cost of sildenafil, talk with your doctor, pharmacist, or insurance provider.Sildenafil Viagra is used to treat erectile dysfunction impotence; inability to get or keep an erection in men. This increased blood flow can cause an erection. You should only be treated with one of these products at a time. Take sildenafil at around the same times every day. If you are taking sildenafil to treat erectile dysfunction, you should know that it does not cure erectile dysfunction or increase sexual desire. What side effects can this medication cause?Viagra: 25 mg, 50 mg, and mg: starting at $ per tablet: lasts 2 to 5 hours: take as needed: Generic Viagra: 25 mg, 50 mg, and mg: starting at $4 per tablet: lasts 2 to 5 hours: take as. 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 . Prices for Sildenafil (Viagra) are as low as $ with a GoodRx coupon. See coupons. What are the side effects of Sildenafil (Viagra)? is to take 50 mg of sildenafil .Follow the manufacturer’s directions to use and clean the oral syringe. Sildenafil treats PAH by relaxing the blood vessels in the lungs to allow blood to flow easily. Make sure you have discussed any other medications you are currently taking or plan to take before starting sildenafil with your doctor and pharmacist. Do not take more or less of it or take it more often than prescribed by your doctor. They enhance the effects of a chemical the body makes that relaxes muscles in the penis, called nitric oxide. The best time to take sildenafil is about 1 hour before sexual activity, but you can take the medication any time from 4 hours to 30 minutes before sexual activity. Sildenafil Viagra.