Use of Intramuscular Chlorpromazine Versus Intramuscular Olanzapine for the Management of Acute Agitation and Aggression in Youth

In the inpatient psychiatric setting, one treatment strategy used to manage acute agitation in youth includes administration of IM antipsychotics. The aim of this study was to compare the effectiveness and safety of IM chlorpromazine versus IM olanzapine in treating aggression in youth. We conducted a retrospective chart review of patients younger than 18 years hospitalized in the inpatient psychiatric unit who received either IM chlorpromazine or IM olanzapine for acute agitation. Demographic, efficacy, and tolerability data were collected using the electronic health record EPIC. The primary outcome was change from baseline to end point in the Behavioral Activity Rating Scale (BARS) score. BARS was applied retrospectively using nursing and physician documentation to evaluate for clinical response. Among 145 patients who met the inclusion criteria, 72 received IM chlorpromazine, compared with 73 who received IM olanzapine. The mean change in BARS score (before and after IM antipsychotic) was greater with olanzapine (3.58 ± 0.99) than with chlorpromazine (3.07 ± 1.18, p = 0.006). The target BARS score of 4 was achieved more frequently with chlorpromazine (45.8%) than with olanzapine (24.7%, p < 0.008). Coadministration of IM diphenhydramine occurred significantly more often in the olanzapine group than in the chlorpromazine group (71.2% vs 36.1%, p < 0.001). Management of acute agitation with IM olanzapine resulted in a greater change in BARS score, despite more youth requiring coadministration with diphenhydramine. In comparison, IM chlorpromazine demonstrated a higher likelihood of returning patients to baseline. Study results suggest tolerability of IM chlorpromazine and olanzapine.