[Mode of action of sildenafil]

Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 1999 Dec;21(6):493-6.
[Article in Chinese]


Sildenafil is the first oral therapeutic agent for erectile dysfunction. Sildenafil is a selective inhibitor of cGMP-specific phosphodiesterase (PDE-5). Penile erection involves relaxation of the corpus cavernosum, an event mediated by NO and cGMP. The biological actions of cGMP are terminated by phosphodiesterase enzymes and PDE-5 is the major cGMP metabolising enzyme in this tissue. Sildenafil is relatively safe compared to erection injectables because it does not relax on isolated human corpus cavernosum, and does not cause priapism. Due to the tendency of abuse of sildenafil, its adverse cardiovascular associations with myocardial infaraction, ventricular arrhythmia and hypertension need to be alerted.

Publication types

  • English Abstract
  • Review

MeSH terms

  • Erectile Dysfunction / drug therapy
  • Fertility Agents, Male / adverse effects
  • Fertility Agents, Male / pharmacology
  • Humans
  • Male
  • Myocardial Infarction / chemically induced
  • Piperazines / adverse effects
  • Piperazines / pharmacology*
  • Purines
  • Sildenafil Citrate
  • Sulfones
  • Vasodilator Agents / adverse effects
  • Vasodilator Agents / pharmacology*


  • Fertility Agents, Male
  • Piperazines
  • Purines
  • Sulfones
  • Vasodilator Agents
  • Sildenafil Citrate