Obsessive compulsive disorder: Opportunities within and beyond the serotonergic domain

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.

Pindolol augmentation in treatment-resistant obsessive compulsive disorder: a double-blind placebo controlled trial

OBJECTIVE

To evaluate the efficacy of pindolol augmentation in treatment-resistant obsessive compulsive disorder (OCD) patients who were unsuccessfully treated with serotonin reuptake inhibitors.

METHOD

Fourteen treatment-resistant OCD patients were treated with paroxetine for 17.4+/-2.1 weeks up to 60 mg/d after they failed at least two other serotonin reuptake inhibitor trials. The patients, who did not respond to open-label paroxetine treatment, were assigned to a double-blind, placebo-controlled pindolol (2.5 mgx3/d) augmentation. All the subjects were evaluated biweekly for a six-week period with the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Hamilton Anxiety Scale (HAM-Anx), and Montgomery Asberg Depression Rating Scale (MADRS). Data was analyzed by paired t-test, and ANOVA with repeated measures.

RESULTS

Pindolol augmentation to paroxetine (n=8) as compared to placebo augmentation (n=6), was associated with a significant (P<0.01) improvement in Y-BOCS as measured by paired t-test after the fourth week of the treatment and by ANOVA with repeated measures (df: 4.9, f: 3,3, P<0.006). Although no significant differences were found between placebo and pindolol groups on HAM-Anx and MADRS, a trend for improvement in the pindolol group was noted.

CONCLUSIONS

The results of our study demonstrated that pindolol may augment the therapeutic effect of paroxetine in treatment-resistant OCD patients.