Do not start these medications while taking sildenafil without discussing it with your healthcare provider. When hypertension occurs in the lungs, the heart must work harder to pump enough blood through the lungs. Ask your doctor if you have any questions. They’re often the first line of treatment for trouble getting or keeping an erection, called erectile dysfunction ED. Children 1 year of age and older weighing 45 kilograms kg or more—20 mg 3 times a day. From Mayo Clinic to your inbox Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health.Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in .  · Descriptions. Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of . What to consider. Cost. Overdose. Ask your doctor. Q&A. Drug Images. What is Viagra? If you have erectile dysfunction (ED), your doctor may recommend that .