Vilitra (vardenafil) works by preventing the secretion of a chemical referred to as phosphodiesterase type-5 (PDE5). Inhibiting PDE5 boosts cGMP and gas, that square measure needed for improved erectile organ blood flow. ED, typically referred to as impotence, means men cannot get or sustain a tough erection. There square measure many physical and psychological causes, with the foremost common being the narrowing of the blood vessels that take blood to the erectile organ.