Silditop 100 is a medication that contains Sildenafil, an active ingredient commonly used to treat conditions like Sexual impotence and PAH. Sildenafil works by relaxing the smooth muscles in the walls of blood vessels, specifically in the pulmonary arteries, which helps reduce the pressure in the lungs and improves blood flow. In essence, it acts as a vasodilator, widening the blood vessels and reducing the strain on the heart.