Comparison of the First Intake of Vardenafil and Tadalafil in Patients with Diabetic Neuropathy and Diabetic Erectile Dysfunction

Abstract

Diabetic neuropathy (DN) is one of the key pathogenetic factors for diabetic erectile dysfunction (DED). The aim of this study was to compare the effect of the first intake of tadalafil and vardenafil in men with DN and DED. In this comparative prospective randomized study were included 49 phosphodiesterase type 5 (PDE5) inhibitor-naïve men (80% type 2 diabetes). DN was assessed by a modified Neuropathy Disability Score (NDS ≥ 3). Each patient received two pills containing 20 mg of either tadalafil (N = 24) or vardenafil (N = 25). They had to be taken after discharge from the hospital at a time interval of at least 3 and 1 day, respectively, and 1 to 6 hours before the intended sexual activity. The treatment efficacy was evaluated by the changes in the erectile domain of International Index of Erectile Function (IIEF), Sexual Encounter Profile Question 2 (SEP2) and 3 (SEP3), and the Global Assessment Question (GAQ). For all patients, IIEF increased from 12.6 ± 6.8 to 19.6 ± 9.0 (P < 0.001) points after treatment. The number of men with positive answers on SEP2 increased from 27 (55.1%) to 38 (77.6%), on SEP3 from 7 (14.3%) to 30 (61.2%). Thirty-one (63.3%) evaluated the effect of the drugs as beneficial (GAQ). No significant efficacy difference between tadalafil and vardenafil was observed. The initial indicators for DED, as well as the treatment efficacy, correlated highly significant with NDS. Both PDE5 inhibitors were well tolerated. Before entering the study, 28% of men have seen a physician, but only 57.1% of them have started treatment. In this study design, tadalafil and vardenafil are equally effective with the first intake in patients with diabetes and DN. Baseline indicators of erectile dysfunction and the ones verifying the effect of the treatment show significant correlation with the DN indicator-NDS. Tadalafil and vardenafil are well tolerated with no serious side effects.