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

Abstract

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.

Keywords

• emergency department
• hospital
• olanzapine
• emergencies
• benzodiazepines
• antipsychotic agents
• parenteral
• intramuscular