Pilot trial of ondansetron in the treatment of 8 patients with obsessive-compulsive disorder.
BACKGROUND
Serotonin (5-HT) neuronal systems have been implicated in the modulation of obsessive-compulsive disorder (OCD) symptoms. 5-HT3 receptor antagonists have been found to act as anxiolytics in selected animal models of anxiety; in particular, those involving an element of risk assessment. Since the compulsions of OCD are frequently triggered by an abnormal perception of risk, a pilot study was initiated to determine whether the 5-HT3 receptor antagonist ondansetron might have efficacy in the treatment of OCD.


METHODS
Eight medication-free subjects with a DSM-IV diagnosis of OCD and a Yale-Brown Obsessive Compulsive Scale (YBOCS) score > or = 16 entered an 8-week open-label trial of ondansetron at a fixed dose of 1 mg 3 times daily in a study conducted between February and October 1998.


RESULTS
Six subjects completed the trial. Three subjects (37%) achieved a clinically significant response (> or = 35% reduction in YBOCS score). For these subjects, the average reduction in YBOCS-rated symptoms was 55%. In aggregate, the 8 patients exhibited a 28% reduction in YBOCS-rated symptoms over the course of the trial. The medication was well tolerated.


CONCLUSIONS
These results suggest that low-dose ondansetron may have promise as a monotherapy for some patients suffering from OCD.
Hewlett
William A
WA
Department of Psychiatry, Vanderbilt University School of Medicine, A-2209 MCN, Nashville, TN 37232, USA. OCD/TS@vanderbilt.edu
Schmid
Sabine P
SP
Salomon
Ronald M
RM
D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D017294:Ondansetron / Q000009:adverse effects / Q000627:therapeutic use*; D010865:Pilot Projects; D058831:Serotonin 5-HT3 Receptor Antagonists; D012702:Serotonin Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D058831:Serotonin 5-HT3 Receptor Antagonists; D012702:Serotonin Antagonists; D017294:Ondansetron