If you are a Mayo Clinic patient, this could include protected health information. Ask your pharmacist for a list of the ingredients. Your doctor may adjust your dose if needed. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Children 1 year of age and older weighing 20 kg or less—10 mg 3 times a day. Call your doctor right away if you have blurred vision, confusion, dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly, sweating, or unusual tiredness or weakness. Follow your doctor’s orders or the directions on the label.The normal dose when starting Viagra is 50 mg, as needed. The maximum dose of Viagra is mg each day. Doses above the maximum dose, such as mg . 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 .  · Descriptions Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines called .