• Score higher than or equal to 21 of the erectile dysfunction domain of the IIEF, or response to treatment [ Time Frame: 42 weeks ]
  
• and/or an affirmative response to the GAQ will be considered for the analysis [ Time Frame: 10 months ]
  

The importance of testosterone in desire, interest and sexual motivation is well known, but its effects on erectile function continue provoking controversy. Data obtained in animals under experimental or surgical castration, explains how this condition can cause a veno-occlusive dysfunction and therefore an erectile dysfunction. In a model of animal flebogenous erectile dysfunction, the intracavernous vascular endothelial growth factor (VEGF), together with testosterone, reestablishes the balance between the muscle and the conjunctive tissue, hypertrophy and hyperplasia of endothelial cells and regularizes the diameter of dorsal nervous cells, thus preventing the veno-occlusive dysfunction. Castration also induces the apopthosis in the erectile tissue of the penis; the treatment with testosterone provokes a new DNA synthesis.

There are certain indicators that the treatment with testosterone could help patients with erectile dysfunction and low testosterone base line amounts. Likewise, androgens could control the expression and the activity of type 5 phosphodiesterase (PDE-5) of the cavernous body of the penis.

Pharmacological treatment with PDE-5 inhibitors, administered orally fails in certain cases of erectile dysfunction, even more in hypogonadal males. Some studies show that the combination of testosterone with a PDE-5 inhibitor helps the recovery of sexual function in patients; therefore, giving the possibility of a combined pharmacological treatment with testosterone in erectile dysfunction.