A double-blind, placebo-controlled pilot study of ondansetron for patients with obsessive-compulsive disorder

Objective To assess the efficacy and tolerability of ondansetron in combination with selective serotonin reuptake inhibitors (SSRIs) in patients with obsessive-compulsive disorder (OCD). Methods The study was an 8-week pilot double-blind randomized clinical trial. Forty-two adult outpatients who met the Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR) criteria for OCD based on the structured clinical interview participated in the trial. In this study, patients were randomly assigned to receive either ondansetron (4 mg) plus fluoxetine or fluoxetine (20 mg/day) plus placebo. Results The results showed a significant difference between two groups in the treatment of OCD (based on t-test). There was not any significant difference between the two groups in terms of observed side effects. Conclusions The results of this study show that ondansetron has positive effects on obsession and compulsion which start two weeks after the beginning of the treatment. Copyright (C) 2010 John Wiley & Sons, Ltd.