??????,??????

??????,??????

??? Viagra????????NO???????????????cGMP????????????????????????

???????????????????????????????????????NO(nitric oxide)????????????(cell signal transduction)????Ca2+ channel?K+ channel???????????????????????????????????????????????



????????????

1998???FDA??????????????????---Sildenafil citrate?????????????(Viagra)???????????????? Viagra????????NO?NO?????guanylate cyclase? cGMP?? cGMP????????????????????????????????

??cGMP?????????(phosphodiesterase)????????????????(phosphodiesterase inhibitor, type 5)-??? Viagra????????????????? Viagra???????????????????????????(acting by inhibiting cGMP-specific phosphodiesterase type 5, an enzyme that promotes degradation of cGMP, which regulates blood flow in the penis)????????????pulmonary arterial hypertension (PAH)?

????????????(???? Sildenafil )??

????:???,???,???,???, ????? (????????????)

????:???,???,??,???,???,??,???,???,???,????,??,??,???,??,??,???,???,??,?? (????????????)

???? ??? ??? ?????

??????

????? Viagra??????????????????4????2??????????????????????????????????(????????????????????)????????????????????????????????????????????????????

???????

????organic nitrites and nitrates???(nitroglycerin, sodium nitroprusside, amyl nitrite)????????????? Viagra?????????????

?????????(cardiovascular risk factors)?

????????(Severe impairment in hepatic or renal function)????? Viagra?????????????

?????(low blood pressure)

???????(Recent stroke or heart attack)

???????????(Hereditary degenerative retinal disorders)

?????????????????????????????????? Viagra????????????(Priapism)?

???????Cimetidine?Erythromycin?Itraconazole?Ketoconazole??????? Viagra???

??????

???????????(16?)?????(10?)?????(7?)???(4?)???(3?)???(2%)???(2?)??????3%?????????????????????????????????????