Comparison of intramuscular haloperidol and other short-acting injectable antipsychotics for management of acute agitation in an adult inpatient psychiatry unit.

INTRODUCTION: There is no consensus on the optimal antipsychotic for acute agitation. Whereas haloperidol is frequently used and has proven efficacy, second generation antipsychotics show similar efficacy and improved safety and tolerability. This study aimed to determine the effectiveness of short-acting intramuscular (IM) haloperidol versus other IM antipsychotics for acute agitation in adults admitted to an inpatient psychiatry unit.

METHODS: This was a retrospective medical record review of patients who received 1 or more doses of a short-acting IM antipsychotic, including chlorpromazine, haloperidol, olanzapine, or ziprasidone. The primary endpoint was the need for subsequent IM antipsychotic(s) or physical restraint within 2 hours of the initial IM antipsychotic. Secondary endpoints assessed outcomes at 24 hours and adverse events.

RESULTS: One hundred six patients were included. Four patients in the haloperidol group and 0 patients in the other antipsychotic group received an additional IM antipsychotic or required physical restraints within 2 hours (5.3% versus 0%, p = .319). More patients in the other antipsychotic group required an additional dose of IM antipsychotic within 24 hours compared with the haloperidol group (p = .0096). More adverse events were seen in patients who received haloperidol.

DISCUSSION: Haloperidol was used more frequently than other short-acting IM antipsychotics. Whereas the effectiveness at 2 hours was not significantly different between groups, patients who received haloperidol were more likely to experience adverse events and were more often subjected to polypharmacy with benzodiazepines and/or diphenhydramine. This study further supports the use of olanzapine and ziprasidone for acute agitation in patients hospitalized in inpatient psychiatry.