Vardenafil is an oral medicine that is used to diagnose impotence, the inability to attain or improve a penile erection. It works similar to sildenafil, and tadalafil. Penile erection is primarily caused by the engorgement of the penis with blood. This engorgement occurs when the blood arteries supplying blood to the penis improve in size and improve the supply of blood to the penis. At the same time, the blood arteries carrying blood away from the penis lessen in size and lower the removal of blood from the penis. Sexual stimulation that begins to the engorgement and erection causes to generate and release of nitric oxide in the penis. Nitric oxide then activates the enzyme, guanylate cyclase to improve cyclic guanosine monophosphate (cGMP). The cGMP is mainly responsible for higher and lower the size of the blood vessels carrying blood to and from the penis. Respectively, vardenafil stop an enzyme known as phosphodiesterase-5 (PDE-5) from devastating cGMP so that cGMP persists longer. The longer cGMP persists. Longer the engorgement of the penis. Vardenafil was approved by the FDA in the USA in the month of august 2003.