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sildenafil citrate The citrate salt of a pyrazolopyrimidinone derivative structurally related to zaprinast. Sildenafil selectively inhibits cyclic guanosine monophosphate (cGMP)-specific type 5 phosphodiesterase, resulting in vasodilation in the corpus cavernosum of the penis and penile erection. Check for active clinical trials or closed clinical trials using this agent. (NCI Thesaurus)
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US brand name: | ![](https://webarchive.library.unt.edu/eot2008/20090115004641im_/http://www.cancer.gov/images/spacer.gif) | Viagra | | ![](https://webarchive.library.unt.edu/eot2008/20090115004641im_/http://www.cancer.gov/images/spacer.gif) |
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