Comparison of open-label, 8-week trials of olanzapine monotherapy and topiramate augmentation of olanzapine for the treatment of pediatric bipolar disorder.

BACKGROUND

The aim of this study was to test the efficacy and safety of olanzapine + topiramate versus olanzapine monotherapy in the treatment of bipolar disorder (BPD) and treatment-attendant weight gain in children and adolescents.

METHOD: Subjects (N = 40) were outpatients of both sexes, 6-17 years of age, with a Diagnostic and Statistical Manual of Mental Disorders, 4(th) edition (DSM-IV) diagnosis of BPD (manic, hypomanic, or mixed) and Young Mania Rating Scale (YMRS) total score of >15 treated over 8-week periods in two partially concurrent open-label trials with olanzapine (n = 17) or olanzapine + topiramate (n = 23).

RESULTS

Subjects in both groups experienced a statistically significant reduction in YMRS scores after 8-week, open-label treatment with olanzapine (baseline YMRS = 26.7 +/- 9.5; end-point YMRS = 18.2 +/- 12.5, p = 0.04) and olanzapine +topiramate (baseline YMRS = 31.3 +/- 7.9; end-point YMRS = 20.4 +/- 11.4, p = 0.04). There was no difference in response between the two groups based on YMRS or Clinical Global Impressions-Improvement (CGI-I) scores. Adverse events were few and mild and similar between the two groups, with the exception of weight gain. The weight gain in the olanzapine group was 5.3 +/- 2.1 kg and the weight gain in the olanzapine + topiramate group was statistically significantly lower, 2.6 +/- 3.6 kg.

CONCLUSIONS

Augmentation of olanzapine with topiramate resulted in a reduced weight gain over the course of an 8-week, open-label trial when compared with olanzapine treatment alone, but did not lead to greater reduction in symptoms of mania.