Sildenafil Liqrev, Revatio is used to improve the ability to exercise in adults Liqrev, Revatio and children 1 year of age and older Revatio with pulmonary arterial hypertension PAH; high blood pressure in the vessels carrying blood to the lungs, causing shortness of breath, dizziness, and tiredness. Some people may also have ringing in their ears tinnitus or dizziness. Take sildenafil exactly as directed. Shake the liquid well for 10 seconds before each use to mix the medication evenly. Follow the manufacturer’s directions to use and clean the oral syringe. Its effects often last for 4 to 5 hours. These medicines all work well for ED.When samples of milligram Viagra tablets purchased online were tested, only 10% were even close to the advertised strength. without a prescription — you won’t get a . Viagra is only available with a prescription in the United States, Canada, and most other countries. Viagra is sold under the generic name sildenafil, which is also only available . No, you should not take Viagra if you don’t have ED. Viagra is a prescription medication that can have serious side effects. And it’s approved only to treat ED, not to be used.