Erectile Dysfunction Medications
Drug therapy for erectile dysfunction was revolutionized with the introduction of phosphodiesterase-5 inhibitors. Until this time it was either a matter of luck with intraurethral alprostadil or a painful and risky procedure of intracavernosal injection with drugs like alprostadil and papaverine. The current treatment approaches primarily revolve around the phosphodiesterase-5 inhibitors like sildenafil.
Phosphodiesterase-5 (PDE-5) inhibitors
Sildenafil, taladafil and vardenafil are the selective PDE-5 inhibitors currently available commercially. All are prescription medicines in the United States and are available as oral tablets. The cyclic-GMP PDE-5 enzyme is believed to be the primary type of phosphodiesterase enzyme present in the cavernosal tissue of the penis. Sexual stimulation leads to increased levels of GMP in the cavernosal tissue of the penis. Cyclic GMP is a muscle relaxing chemical which allows for increased blood flow to the penis and filling of the corpora cavernosa.