Oral testosterone undecanoate reverses erectile dysfunction associated with diabetes mellitus in patients failing on sildenafil citrate therapy alone.

AIMS: To evaluate the cause of failure of sildenafil citrate (Viagra) to restore erections in patients with organic erectile dysfunction (ED) associated with type II diabetes mellitus (DM) and receiving oral antidiabetic drugs.

METHODS: Diabetic ED patients (n = 120), aged 43-74 years, failing to respond at least three times to 100 mg Viagra were evaluated. After at least 2 weeks' treatment with oral testosterone undecanoate (Andriol), 100 mg Viagra was used before coitus. ED was assessed with the International Index of Erectile Function (IIEF). Serum total testosterone, prolactin, thyroid stimulating hormone, lipid profile and prostate-specific antigen (PSA) were determined by standard methods and prostate volume by digital rectal examination. Age-matched diabetic ED patients (n = 100) served as controls for baseline values.

RESULTS: Viagra non-responders had, at baseline, significantly lower testosterone and more depressed libido than controls. Andriol restored testosterone to normal levels and increased libido. In 84/120 (70%) Viagra non-responders, combined therapy with Andriol induced satisfactory erections, a significant increase in IIEF scale (question (Q) 3 from 2.0 +/- 0.2 to 3.7 +/- 0.3, Q4 from 1.9 +/- 0.1 to 3.4 +/- 0.2, Q12 from 1.0 +/- 0.1 to 4.2 +/- 0.4) and increased sexual contacts from 0.5 to 3-4 per month. No adverse events were noted, and PSA levels remained below 4 ng/ml.

CONCLUSION: Decreased testosterone levels in patients with ED and type II DM receiving oral antidiabetic against may be responsible for failure to respond to sildenafil citrate therapy. Combination with oral testosterone undecanoate restores sexual function in these patients.