Sildenafil in the Treatment of Antipsychotic-Induced Erectile Dysfunction: A Randomized, Double-Blind, Placebo-Controlled, Flexible-Dose, Two-Way Crossover Trial

OBJECTIVE: Antipsychotic-induced erectile dysfunction is a significant clinical problem and is a common reason for poor medication compliance. This report studied the efficacy and tolerability of sildenafil citrate in patients with antipsychotic-induced erectile dysfunction. METHOD: The study design was a randomized, double-blind, placebo-controlled, flexible-dose, two-way crossover trial carried out at a tertiary referral center. Thirty-two married male outpatients with schizophrenia or delusional disorder and antipsychotic-induced erectile dysfunction were recruited for the trial. Sexual function was assessed from patient logs of sexual activity. RESULTS: Thirty-two subjects and their spouses, who agreed to take part in the study, were included in the crossover trial. Thirty-one (96.9%) completed the trial. There was no significant period effect or treatment-period interaction. Patients reported significant improvement while taking sildenafil in the number of adequate erections, satisfaction with sexual intercourse, and the duration of erections over 2 weeks. The odds ratios for adequate erections and for satisfactory sexual intercourse with sildenafil were 4.07 and 3.77, respectively. The effect of sildenafil remained significant even after adjustment for period and week effects and treatment-period interaction with Poisson regression analysis. There were no major side effects or adverse drug interactions. CONCLUSIONS: Sildenafil citrate is safe and effective in the treatment of antipsychotic-induced erectile dysfunction. It is also well tolerated.