Sildenafil can be a potent and selective inhibitor of cGMP-unique phosphodiesterase sort 5 (PDE5), and that is answerable for degradation of cGMP while in the corpus cavernosum. The molecular structure of sildenafil is analogous to that of cGMP and acts like a aggressive binding agent of PDE5 during the corpus cavernosum, leading to extra cGMP and