Comparing Intubation Rates in Patients Receiving Parenteral Olanzapine With and Without a Parenteral Benzodiazepine in the Emergency Department.

Study objective: United States prescribing information recommends against coadministration of injectable olanzapine with injectable benzodiazepines due to a risk of cardiorespiratory depression, whereas European prescribing information recommends the 2 drugs not be administered within 60 minutes of each other. In contrast, a recently published American College of Emergency Physicians clinical policy recommends injectable olanzapine and benzodiazepines be coadministered for treating severe agitation. We sought to compare injectable olanzapine with and without injectable benzodiazepines for evidence of cardiorespiratory depression.

Methods: We performed a retrospective study of patients in an urban emergency department from January 2017 through November 2019 who received parenteral olanzapine with or without parenteral benzodiazepines. We included patients receiving 2 total medication doses, either olanzapine+benzodiazepine or 2 doses of olanzapine, coadministered within 60 minutes. The primary outcome was tracheal intubation in the emergency department. Secondary outcomes included hypotension (systolic blood pressure less than 90 mmHg) and hypoxemia (SpO₂ less than 90%).

Results: We identified 693 patients (median [alcohol]=210 mg/dL, median age=37 years [IQR 29 to 49]). In total, 549 received 2 doses of olanzapine, and 144 patients received olanzapine and a benzodiazepine. We found no difference in intubation rates between the olanzapine-only group (21/549, 3.8%) and the olanzapine+benzodiazepine group (5/144, 3.5%; difference=0.3%, 95% confidence interval -3.0% to 3.7%). Rates of hypoxemia (2% olanzapine-only and 3% olanzapine+benzodiazepine) and hypotension (9% both groups) also were not different between groups.

Conclusion: We found no difference in cardiorespiratory depression between patients receiving only olanzapine versus olanzapine plus a benzodiazepine.