Safety and efficacy of olanzapine monotherapy in treatment-resistant bipolar mania: a 12-week open-label study

Abstract

Objective: To examine the safety and efficacy of olanzapine monotherapy in treatment-resistant bipolar mania.

Method: Subjects (n = 18) who were acutely manic, did not respond to lithium, anticonvulsants, and neuroleptics, and/or had intolerable side effects to them in previous manic episodes were openly treated with olanzapine monotherapy (5-40 mg/d) for 12 weeks. The primary and secondary outcomes included the change from baseline to endpoint in Young Mania Rating Scale (YMRS) total score, Clinical Global Impression for Bipolar Disorder-Severity Scale (CGI-S), 17-item Hamilton Depression Rating Scale (HAM-D) and Positive and Negative Syndrome Scale (PANSS), and response and remission rate.

Results: The mean change in YMRS total score from baseline to endpoint was -23.3 ± 8.4 (p < 0.001). Fifteen (88.5%) patients achieved response (≥50% reduction in YMRS total score) and 14 (77.8%) achieved remission (YMRS total score ≤9 at endpoint). Mean changes from baseline to endpoint in CGI-S for mania and PANSS total score were significant, but not the changes in HAM-D total score or CGI-S for depression. The most common adverse events were sedation, self-reported weight gain, ≥7% increase in body weight, dizziness, and akathisia.

Conclusions: These preliminary results suggest that olanzapine monotherapy is effective and relatively safe in patients with treatment-resistant bipolar mania. Randomized, double-blind, placebo-controlled study is warranted.