Comparison of the clinical efficacy of daily use of L-arginine, tadalafil and combined L-arginine with tadalafil in the treatment of elderly patients with erectile dysfunction.

: This study aimed to evaluate the efficacy of the daily oral administrations of L-arginine, tadalafil and combined L-arginine with tadalafil in treatments of elderly patients with erectile dysfunction (ED). It was designed as a single-blind placebo-controlled clinical trial. It was conducted on 120 male patients aged ≥60 years old with ED. Patients were randomised classified into four groups (n = 30 each). Oral daily use of L-arginine (5 g), tadalafil (5 mg), combined L-arginine (5 g) with tadalafil (5 mg) and placebo were taken for 6 weeks in each group of patients respectively. Patients were assessed before and after treatments using the Sexual Health Inventory for Men (SHIM) questionnaire and total serum testosterone. The means of Q1-5, total scores of SHIM and total testosterone, in L-arginine, tadalafil and combined L-arginine with tadalafil groups were significantly higher after treatments (p = .001). Combined L-arginine with tadalafil group had the highest SHIM scores and levels of total testosterone. This clinical trial deduced that the combined daily use of L-arginine with tadalafil therapy for elderly male patients with ED could significantly increase the SHIM scores and levels of total testosterone in comparison to L-arginine, or tadalafil alone.