Ondansetron in combination with fluoxetine for obsessive–compulsive disorder: A randomized, double-blind, placebo-controlled study from North India

Abstract

BACKGROUND: A large percentage of patients with obsessive–compulsive disorder (OCD) do not respond to first-line medications. Ondansetron, a 5-HT3 receptor antagonist, has been shown to be effective in the treatment of OCD as an augmentation agent to selective serotonin reuptake inhibitors. However, scientific evidence in this regard is limited. AIMS: This study aimed to study the effect of ondansetron in combination with fluoxetine on psychopathology, functioning, and quality of life in patients with obsessive–compulsive disorder and to compare these parameters with patients treated with fluoxetine alone. METHODS: This was a 12-week prospective, randomized, double-blind, placebo-controlled study. Patients fulfilling diagnostic criteria for OCD on the basis of the International Classification of Diseases 10-DCR and having a score of ≥4 clinical global impression-severity (CGI-S) were enrolled in the study. The patients received either fluoxetine with Ondansetron (4 mg/day in two divided doses) or fluoxetine with placebo randomly for a period of 12 weeks. The patients were assessed using the Yale–Brown Obsessive–Compulsive Scale (Y-BOCS), Social and Occupational Functioning Assessment Scale, CGI, WHO Quality of Life-BREF, and an adverse event checklist at baseline and at weeks 4, 8, and 12. Seventy patients completed the study. Results: The Y-BOCS total score, obsession subscale score, and compulsion subscale score showed a significantly greater reduction in the ondansetron group than in the placebo group. Improvement in functioning and quality of life was significantly higher in ondansetron group than in placebo group. There was no statistically significant difference between the two groups in terms of side effects. Conclusion: A significant beneficial effect of combining ondansetron to fluoxetine in patients with OCD was observed.