Novel therapeutic targets for erectile dysfunction.

Erectile dysfunction (ED) is a neurovascular phenomenon modulated by hormonal, local biochemical, and biomechanical/structural factors of the penis. The success of the orally active phosphodiesterase inhibitors for the treatment of ED has boosted research activities into the physiology of the erectile mechanism. Peripheral intracellular signal transduction in the penis as well as central brain and spinal cord pathways controlling penile erection have been investigated and are now better understood. The results of this ongoing research have provided the basis for the development and introduction of several novel therapeutic modalities into the management of ED. Many novel pharmacotherapeutic approaches under development including the use of melanocortins and Rho-kinase inhibitors as well as the introduction of gene therapy and tissue engineering have demonstrated efficacy in animal as well as early human trials. This review describes the major new and evolving pharmacological advances in the field of oral pharmacotherapy for the treatment of male ED.