A comparison of the safety of olanzapine and haloperidol in combination with benzodiazepines in emergency department patients with acute agitation

J Emerg Med. 2012 Nov;43(5):790-7. doi: 10.1016/j.jemermed.2011.01.024. Epub 2011 May 20.


Background: Pharmacologic management of the agitated emergency department patient is controversial. The combination of olanzapine + benzodiazepines is not recommended by the manufacturer, but a recent report suggested harm only if the patient was intoxicated. Whether this is also true for haloperidol + benzodiazepines is not known.

Objectives: The measurement of vital signs and ethanol levels in patients who received haloperidol with or without benzodiazepines was compared to a previous analysis of patients who received olanzapine with or without benzodiazepines.

Methods: This is a structured retrospective chart review of patients who received parenteral haloperidol or parental olanzapine either with or without benzodiazepines.

Results: There were 96 patients (71 haloperidol, 25 olanzapine) who met inclusion criteria. No patient in the olanzapine + benzodiazepine group had hypotension, although one patient in the olanzapine-only group did (6.7%); 2 patients in the haloperidol + benzodiazepines group (5.1%) and 2 patients in the haloperidol-only group (6.3%) had hypotension. In alcohol-negative (ETOH-) patients, neither olanzapine alone nor olanzapine + benzodiazepines was associated with decreased oxygen saturations. In ETOH+ patients, olanzapine alone was not associated with decreased oxygen saturations, but olanzapine + benzodiazepines were associated with lower oxygen saturations than haloperidol + benzodiazepines.

Conclusions: In this sample, olanzapine alone or with a benzodiazepine was not associated with more hypotension than haloperidol. However, olanzapine + benzodiazepines were associated with lower oxygen saturations than haloperidol + benzodiazepines in ETOH+ but not ETOH- patients. In patients with known alcohol ingestion, haloperidol, haloperidol + benzodiazepines, or olanzapine alone may be better choices for treatment of agitation.

MeSH terms

  • Acute Disease
  • Adult
  • Alcoholic Intoxication / drug therapy
  • Alcoholic Intoxication / physiopathology
  • Analysis of Variance
  • Antipsychotic Agents / adverse effects
  • Antipsychotic Agents / therapeutic use*
  • Benzodiazepines / adverse effects
  • Benzodiazepines / therapeutic use*
  • Blood Pressure / drug effects
  • Drug Interactions
  • Drug Therapy, Combination / methods
  • Emergency Service, Hospital
  • Female
  • Haloperidol / adverse effects
  • Haloperidol / therapeutic use*
  • Humans
  • Male
  • Middle Aged
  • Olanzapine
  • Oxygen / blood
  • Psychomotor Agitation / drug therapy*
  • Psychomotor Agitation / physiopathology
  • Retrospective Studies


  • Antipsychotic Agents
  • Benzodiazepines
  • Haloperidol
  • Olanzapine
  • Oxygen