羟基硫代豪莫西地那非是西地那非的硫代类似物，据报道是PDE5抑制剂。西地那非是5型cGMP磷酸二酯酶（PDE5）的选择性抑制剂，可催化cGMP的水解，cGMP是多种细胞过程中的重要次级信使分子。据报道，西地那非可增强中风大鼠模型的血管生成，并且据报道是一种轻度的血管扩张药。西地那非已显示可通过依赖于NO / cGMP的机制预防吲哚美辛诱导的小肠溃疡形成。 Hydroxythiohomo Sildenafil is a thio analog of Sildenafil which has been reported to be a PDE5 inhibitor. Sildenafil is a selective inhibitor of type 5 cGMP phosphodiesterase (PDE5), which catalyzes teh hydrolysis of cGMP, an important secondary messenger molecule in a variety of cellular processes. Sildenafil has been reported to enhance angiogenesis in rat models of stroke and also has been reported to be a mild vasodilator. Sildenafil has been shown to prevent indomethacin-induced small intestinal ulceration formation throuh an NO/cGMP-dependent mechanism.