An observational study of the effectiveness and safety of intramuscular olanzapine in the treatment of acute agitation in patients with bipolar mania or schizophrenia/schizoaffective disorder

Objective To determine the effect of intramuscular (IM) olanzapine in severely agitated patients. Methods This was an open-label multicenter 1-week observational study of IM olanzapine treatment in severely agitated inpatients and psychiatric emergency services with bipolar mania (n = 22) or schizophrenia (n = 52). Mean change from baseline to 2 h post-first injection (LOCF) in agitation was assessed by PANSS-Excited Component (PANSS-EC) (score range: 5–35 points) mean change from baseline to 15, 30, 45, 60, 90, and 120 min post-first injection, and visit-wise mean changes from mixed-model repeated measures analysis of variance. Kaplan–Meier survival curve analyses estimated time to categorical response (rating of ≤3 points each PANSS-EC item). Results Two hours post-injection of olanzapine (mean dose = 9.9 mg), patients exhibited mild calmness and agitation was significantly reduced by 19.2 ± 1.0 points (p < 0.001) (mean baseline = 29.0). Over 90% of the patients received only one injection in the first 24 h and 50% had a categorical response within 30 min. Conclusions Severely agitated patients responded rapidly after a single injection of olanzapine with mild levels of sedation and without serious treatment-emergent adverse events. Copyright © 2007 John Wiley & Sons, Ltd.