Testosterone therapy can enhance erectile function response to sildenafil in patients with PADAM: a pilot study

Recent studies suggest a direct relationship between free testosterone and cavernous vasodilatation. Some men with erectile dysfunction (ED) associated with PADAM (partial androgen deficiency in aging men) might possibly benefit from testosterone undecanoate therapy (TRT).

To determine the efficacy of testosterone undecanoate in facilitating the erectile response and patient satisfaction with sildenafil in men 40-70 years old with PADAM symptoms.

Prospective study including 40 patients recruited after a sildenafil therapeutic trial. Total testosterone and sex hormone binding globulin (SHBG) were measured to calculate the free androgen index. Prostate specific antigen (PSA) was measured and repeated 2 months after treatment. A rating score was used for PADAM symptoms, and the 5-point abbreviated version of the International Index of Erectile Function (IIEF-5) to assess erectile function. Men failing to respond to sildenafil were randomized into two groups receiving sildenafil plus continuous TRT (group 1ST), and TRT (group 1T) alone. Men partially responding to sildenafil were randomized into two groups receiving sildenafil plus continuous TRT for 2 months (group 2ST), or sildenafil alone (group 2S). Treatment efficacy was assessed by analysis of between-group differences.

Groups 1T, 2S, and 2ST showed significant improvement in PADAM scores (P<0.05, Wilcoxon matched pairs test). Patients receiving both sildenafil plus continuous TRT (groups 1ST and 2ST) showed significant improvement in IIEF-5 scores (P<0.5, paired t-test). No significant changes in serum levels of PSA were detected (paired t-test).

We conclude that TRT appears to be beneficial and safe in facilitating the erectile response and patient satisfaction with sildenafil in men with PADAM symptoms. Androgen supplementation should be carried out cautiously with careful monitoring to avoid possible adverse effects.