Describe the clinically important drug interactions of sildenafil. In addition, ED is extremely common. Take sildenafil at around the same times every day. Adverse Effects Warnings and Precautions Sildenafil has systemic vasodilatory effects and, as such, should be prescribed with caution to patients who may be sensitive to such blood pressure changes, such as patients with left ventricular outflow obstruction and impaired autonomic control of blood pressure. Cialis reaches its maximum effectiveness two hours after you take it. Dosage and strength for pulmonary hypertension Sildenafil tablets for pulmonary hypertension come in 10mg and 20mg strengths.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 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 . Sildenafil Citrate Coupons, Prices, and Savings Card. Brand Names: Revatio, Viagra. Sildenafil is used to treat male sexual function problems (impotence or erectile dysfunction-ED). Learn more about sildenafil oral. 1. Sildenafil is used to treat high blood pressure in the lungs (pulmonary hypertension). The dose can be increased to mg or decreased to 25mg depending on its effect. Take sildenafil up to 4 hours before you want to have sex. For sildenafil to work properly, you’ll need to be sexually excited. Dosage and strength for pulmonary hypertension. Sildenafil tablets for pulmonary hypertension come in 10mg and 20mg strengths.