Intramuscular olanzapine versus intramuscular aripiprazole for the treatment of agitation in patients with schizophrenia: A pragmatic double-blind randomized trial

Abstract

Objective: To evaluate and compare the effectiveness and adverse effects of intramuscular (IM) olanzapine and IM aripiprazole for the treatment of agitated patients with schizophrenia in clinical practice.

Methods: A 24-hour randomized double-blind study carried out at a psychiatric hospital in Thailand enrolled adult patients (18-65years old) with schizophrenia experiencing agitation. Patients received one dose of IM olanzapine or IM aripiprazole followed by routine oral psychotropic medications. Efficacy was primarily measured using the Excited Component of the Positive and Negative Syndrome Scale (PANSS-EC).

Results: A total of 80 patients with a PANSS-EC score range of 22-35 entered the study, of whom 13% had a medical comorbidity and 40% a history of active substance abuse. The 40 patients receiving IM olanzapine showed greater improvement than the 40 patients receiving IM aripiprazole in PANSS-EC scores at 2h after the injection (p=0.002) but not at 24h. The two treatments were well tolerated. Patients receiving IM olanzapine experienced greater somnolence than those receiving IM aripiprazole. There were no clinically relevant changes in vital signs in either group.

Conclusion: The results indicate that IM olanzapine and aripiprazole are similarly effective and well tolerated in the real-world treatment of agitation associated with schizophrenia over the first 24h. However, in the early hours, IM olanzapine may produce more sedation and reductions in agitation.

Keywords: Agitation; Aripiprazole; Intramuscular; Olanzapine; Schizophrenia.