Objectives: To determine the effectiveness and safety of high-dose yohimbine for the treatment of mixed-type impotence.
Methods: Twenty-nine patients who had mixed-type impotence diagnosed on the basis of a sexual history, results of a physical examination, laboratory analysis, assessment of the sensory pain threshold of the dorsal nerve of the penis, and dynamic color Doppler sonography of the cavernosal arteries were entered into a randomized, double-blind, placebo-controlled, crossover comparison of a placebo with high-dose yohimbine hydrochloride (36 mg per day orally). The treatment consisted of two 25-day courses; after a 14-day washout period, the patients who initially received the placebo for 25 days were switched to yohimbine hydrochloride for 25 days. Erectile function, ejaculation, interest in sex, physical examination findings, blood pressure, pulse rate, weight, and audiovisual sexual stimulation test were investigated before treatment and at the end of each drug period. The Mann-Whitney test was used for the statistical analysis.
Results: Twenty-seven patients (93%) completed the whole treatment schedule. Positive clinical results (complete and partial responses) were obtained in 12 cases (44%) at the end of the yohimbine phase and in 13 (48%) after the placebo period. No statistical difference was indicated. Drug-related adverse effects occurred in 2 patients in the yohimbine group (7%).
Conclusions: Yohimbine is no better than placebo as a first-line treatment for mixed-type impotence.