ISPAM Working Group Chair Presentation Book

Phosphodiesterase Type 5 (PDE5) Inhibitors • Used in the treatment of erectile dysfunction (ED) and also  explored for the treatment of pulmonary hypertension  • Block degradative action of PDE5 on cyclic guanosine monophosphate (cGMP) in smooth muscle cells lining the blood  vessels supplying the corpus cavernosum of the penis (and  arterial walls within the lungs)

• cGMP – second messenger which relaxes smooth muscle  cGMP tissues, leading to the increased blood flow in blood vessels