A retrospective review of intramuscular olanzapine and parenteral benzodiazepine coadministration in the emergency department.

INTRODUCTION: Acute agitation is a common presenting symptom in medical and mental health emergencies that may require pharmacologic intervention. There is a manufacturer recommendation against intramuscular coadministration of olanzapine with parenteral (intramuscular or intravenous) benzodiazepines despite a deficiency of high-quality evidence. The purpose of this study was to contribute to available literature regarding intramuscular olanzapine and parenteral benzodiazepine use in acutely agitated patients in the emergency department (ED).

METHODS: This was a single-center retrospective chart review of adult ED patients who received intramuscular olanzapine and a parenteral benzodiazepine within 2 hours. The composite primary endpoint evaluated the occurrence of cardiac or respiratory compromise within 2 hours of medication administration. Secondary endpoints mirrored the primary endpoint within 30 minutes and evaluated the occurrence of cardiac arrest or desaturation in the ED outside the 2-hour window.

RESULTS: One hundred eleven patients were included in the analysis, 64 (57.7%) of whom had documented vitals or oxygen status within 2 hours of medication administration. The composite primary endpoint occurred in 8 patients (12.5%), with only 1 patient requiring intervention with intravenous fluids. The secondary composite endpoint occurred in 2 (9.5%) of 21 patients with documented vitals or oxygen status within 30 minutes of treatment, neither of which required intervention. There were no identified events of intubation or significant cardiac events.

DISCUSSION: Until better evidence is available, this combination therapy should, at minimum, include appropriate patient monitoring. Future studies should investigate risk factors for serious adverse effects.