Background: Patients with schizophrenia and bipolar disorder have frequently reported weight gain during olanzapine treatment. Previous studies have observed a decrease in weight gain, or weight loss, in patients switching from standard olanzapine tablets (SOT) to orally disintegrating olanzapine (ODO) tablets. The primary objective of this study was to investigate the change in body mass index (BMI) in patients who had previously gained weight with SOT and continued with this therapy during the study period, compared with those patients who switched to ODO during the study period.
Methods: This was a 16-week, multicentre, randomized, double-blind, double-dummy, study of outpatients diagnosed with schizophrenia, schizoaffective disorder, related psychotic disorder or bipolar disorder, who were taking 5-20 mg SOT daily. Patients continued treatment with 5-20 mg olanzapine in a flexible single daily dose, and were randomized to either receive sublingual ODO plus an oral placebo, or sublingual placebo plus SOT.
Results: No statistically significant between group differences in mean change from baseline in BMI, weight or waist circumference were observed. Analysis of change in body weight from baseline, by pre-specified category (no change, loss of >or=1.5 kg, gain of >or=1.5 kg), revealed a significant difference between groups, favoring ODO patients, who also experienced a significant reduction in subjective appetite and better treatment compliance, compared to patients in the SOT group.
Conclusions: In this study, patients treated with ODO experienced a similar mean change in BMI and weight from baseline, to those patients treated with SOT.