A double-blind, randomized comparison study of efficacy and safety of intramuscular olanzapine and intramuscular haloperidol in patients with schizophrenia and acute agitated behavior

Studies of intramuscular (IM) olanzapine in Asian and Taiwanese populations are limited. This study examined the efficacy and safety of IM olanzapine in Taiwanese patients with schizophrenia and acute agitated behavior.This was a multicenter, double-blind, randomized, parallel study comparing the efficacy and safety of 10 mg/d IM olanzapine (n = 25) against 7.5 mg/d haloperidol (n = 24). The primary objective was to assess the change of agitation from baseline to 2 hours after the first IM injection on the Positive and Negative Symptom Scale-Excited Component Scale.The changes of Positive and Negative Symptom Scale-Excited Component Scale score from baseline to 2 hours after the first IM injection did not show statistically significant difference between study groups (olanzapine -9.0 ± 5.7, haloperidol -7.9 ± 4.0, P = 0.254). Both groups reported insomnia as the most common treatment-emergent adverse event, and no serious adverse event was reported.Intramuscular olanzapine and IM haloperidol are similarly effective antipsychotic agents in treating agitated symptoms in Taiwanese patients with schizophrenia. Both IM olanzapine and IM haloperidol were proven to be safe and well tolerated, which also provided alternative options in the treatment of patients with schizophrenia with agitation.