Schwarz E R, Kapur V, Rodriguez J, Rastogi S, Rosanio S
Division of Cardiology, Cedars Sinai Medical Center, Los Angeles, CA 90048, USA.
Int J Impot Res. 2007 Mar-Apr;19(2):139-48. doi: 10.1038/sj.ijir.3901491. Epub 2006 Jun 8.
Phosphodiesterase-5 (PDE-5) inhibitors selectively inhibit PDE-5 enzymes that are present in various tissues like penile tissue, platelets, vascular, and smooth muscle tissue. The drug's actions on these tissues have lead to the successful therapeutic use in patients suffering from conditions such as erectile dysfunction (ED) and pulmonary hypertension. PDE-5 inhibitors (PDE-5i) act on the erectile tissue causing penile smooth muscle relaxation and vasodilatation leading to penile erection. In addition, in particular when used in conjunction with prostaglandin inhibitors, PDE-5i cause vasodilatation in pulmonary vasculature hence decreasing both the pulmonary arterial pressure and resistance. PDE-5i have also shown to mildly decrease blood pressure, increase cardiac index, and increase coronary blood flow in experimental animals as well as in human studies. The Food and Drug Administration (FDA) has approved three PDE-5i for the treatment of ED: sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis) and one for pulmonary hypertension: sildenafil (Revatio). These agents are highly selective for PDE-5 enzymes as compared to other subclasses of PDE enzymes and have the almost identical pharmacological action but slightly different pharmacokinetics. Only little data exist about long-term use of PDE-5i and their effects on different organ system. This paper reviews the current information available on chronic PDE-5 inhibitor use.
磷酸二酯酶-5(PDE-5)抑制剂可选择性抑制存在于多种组织(如阴茎组织、血小板、血管和平滑肌组织)中的PDE-5酶。该药物对这些组织的作用已使其成功用于治疗勃起功能障碍(ED)和肺动脉高压等疾病的患者。PDE-5抑制剂(PDE-5i)作用于勃起组织,使阴茎平滑肌松弛和血管扩张,从而导致阴茎勃起。此外,特别是与前列腺素抑制剂联合使用时,PDE-5i可使肺血管舒张,从而降低肺动脉压和阻力。在实验动物以及人体研究中,PDE-5i还显示出可轻度降低血压、增加心脏指数和增加冠状动脉血流量。美国食品药品监督管理局(FDA)已批准三种PDE-5i用于治疗ED:西地那非(万艾可)、伐地那非(艾力达)和他达拉非(希爱力),以及一种用于治疗肺动脉高压的药物:西地那非(Revatio)。与PDE酶的其他亚类相比,这些药物对PDE-5酶具有高度选择性,并且具有几乎相同的药理作用,但药代动力学略有不同。关于PDE-5i的长期使用及其对不同器官系统的影响,现有数据很少。本文综述了有关慢性使用PDE-5抑制剂的现有信息。