A Large Retrospective Cohort of Patients Receiving Intravenous Olanzapine in the Emergency Department.

BACKGROUND: Olanzapine is an atypical antipsychotic with similar pharmacologic properties to droperidol. Due to the current droperidol shortage, the authors' clinical practice has been to substitute olanzapine for droperidol in many situations. At this time, olanzapine is U.S. Food and Drug Administration approved for oral and intramuscular (IM) use only, but due to its increased utility, intravenous (IV) olanzapine was recently approved for use in the study emergency department (ED).

OBJECTIVES: The authors sought to review the use and safety of IV olanzapine in the ED patient population.

METHODS: A retrospective review of consecutive patients receiving IV olanzapine between January 1, 2014, and July 1, 2014, was conducted. Data were collected via an electronic medical record review. The study was deemed exempt from informed consent by our institutional review board.

RESULTS: A total of 713 patients received IV olanzapine during the study period. The median age was 38 years (range = 18 to 85 years), and 313 patients were male (43.9%). Primary indications for IV olanzapine administration included acute agitation (n = 245, 34.4%), abdominal pain (n = 165, 23.1%), headache (n = 121, 17.0%), nausea and vomiting (n = 107, 15.0%), pain (other; n = 60, 8.4%), and unknown (n = 15, 2.1%). IV dosing varied: 1.25 mg (n = 20, 2.8%), 2.5 mg (n = 185, 25.9%), 5 mg (n = 507, 71.1%), and 10 mg (n = 1, 0.1%). Forty-nine patients required a second dose of olanzapine (22 IV, 26 IM, one oral). The maximum total dose of olanzapine was 20 mg. Ninety-eight patients required a total of 146 doses of additional sedatives during their ED course. Other sedative medications included ketamine (n = 17, 2.4%), haloperidol (n = 48, 6.7%), and benzodiazepines (n = 81, 11.4%). Hypoxia was noted in 74 patients (10.4%). Major respiratory complications, including airway stimulation or repositioning maneuvers and intubation, occurred in 15 patients (2.1%). After consensus review, one intubation was classified as "likely related" to olanzapine administration, and two were classified as "possibly related" to olanzapine. Akathisia likely occurred in four patients (0.6%), and no allergic reactions were identified. Electrocardiograms (ECGs) were performed in 322 patients. A total of 251 patients had an ECG performed before olanzapine administration (median QTc = 404 ms), and 88 patients had an ECG performed after olanzapine administration (median QTc = 415 ms). Acute alcohol and drug intoxication was common, 118 (16.5%) patients were positive for ethanol, and seven of 23 drug screens were positive for sympathomimetics. Thirty-four of 284 admissions (4.5%) were to intermediate or intensive care unit beds. No patients died while in the ED and no cases of sudden cardiac death were noted.

CONCLUSIONS: In this large retrospective review, IV olanzapine appears to be a safe in the management of a variety of ED indications. Hypoxia was common, but serious airway compromise was rare.