Sildenafil citrate is a selective inhibitor of cyclic guanosine monophosphate (cGMP) - specific phosphodiesterase type 5 (PDE5) which is the predominant PDE isoenzyme in human corpora cavernosa. In there, nitric oxide (NO) activates the enzyme guanylate cyclase, which results in increased levels of cGMP. Sildenafil enhances the effect of NO by inhibiting PDE5, which is responsible for degradation of cGMP in the corpus cavernosum. Recently, sildenafil citrate has been indicated for the treatment of pulmonary arterial hypertension and Alzheimer's disease
et al.For reference, we also have related compounds/synthetic intermediates [
E1134] [
M2773] of sildenafil. (The product is for research purpose only.)