Proper Use Use sildenafil exactly as directed by your doctor. Bleeding disorders, history of or Stomach ulcer, or history of or—Chance of problems occurring may be increased. Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient. What side effects can this medication cause? Also tell your doctor if you or any of your family members have or have ever had an eye disease such as retinitis pigmentosa an inherited eye condition that causes loss of vision or if you have ever had sudden severe vision loss, especially if you were told that the vision loss was caused by a blockage of blood flow to the nerves that help you see. Shake the liquid well for 10 seconds before each use to mix the medication evenly. Although not all of these side effects may occur, if they do occur they may need medical attention.Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum recommended dose is mg. Don’t take sildenafil (Viagra) more than once daily (at any dose). Written by Brian Leonard, PharmD, BCACP, BCGP. AdEnjoy Greater Libido & Performance. Fast Express ries: Aphrodisiacs, Best Sellers, Energy, Herbal Incense, Herbal Tea and more. Sildenafil (Generic Viagra, Revatio) is medication used to treat erectile dysfunction (ED) in men who suffer from impotence, or the inability to get or maintain an combination with sexual stimulation, sildenafil works by increasing blood flow to the penis to help a man get an erection and maintain it during sexual intercourse.