Children 1 year of age and older weighing 45 kilograms kg or more—20 mg 3 times a day. If you are taking sildenafil to treat erectile dysfunction, follow your doctor’s directions and the guidelines in this paragraph. Smith1; Mary Babos2. Off-labeled Uses Sildenafil is also occasionally used off-label for the treatment of secondary Raynaud phenomenon, female sexual arousal disorder, and as an adjunct in the treatment of altitude-induced hypoxemia. This product is available in the following dosage forms: Tablet Suspension There is a problem with information submitted for this request. 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 comes as a tablet and suspension (liquid) to take by mouth. If you are taking sildenafil to treat erectile dysfunction, follow your doctor’s directions and the guidelines .  · Before taking this medicine. You should not use sildenafil if you are allergic to it, or: if you take other medicines to treat pulmonary arterial hypertension, such as . Sildenafil should be used with caution in men taking an alpha-blocker (especially doxazosin). Hypotension is more likely to occur within four hours following treatment with .