Efficacy of Combination Haloperidol, Lorazepam, and Diphenhydramine vs. Combination Haloperidol and Lorazepam in the Treatment of Acute Agitation: A Multicenter Retrospective Cohort Study

Background: Antipsychotic and sedative combinations are commonly used for treating agitation in the emergency department despite limited evidence regarding their comparative safety and efficacy. Objectives: To compare the efficacy and safety of combination haloperidol, lorazepam, and diphenhydramine (B52) to combination haloperidol and lorazepam (52) in treating acute agitation. Methods: This multicenter, retrospective cohort study included adult patients ≥ 18 years of age who received either B52 or 52 at a Banner Health facility between August 2017 and September 2020. Patients were excluded if they had a pre-existing movement disorder or were withdrawing from alcohol. The primary outcome was administration of additional agitation medication(s) within 2 h of B52 or 52. Secondary outcomes included incidence of extrapyramidal symptoms, length of stay, and additional safety measures. Results: There was no difference in administration frequency of additional agitation medication(s) (B52: n = 28 [14%] vs. 52: n = 40 [20%]; p = 0.11). Patients who received 52 were more likely to require an antimuscarinic medication within 2 days (15 vs. 6 patients, p = 0.04). Of the patients who received an antimuscarinic medication, none had documented extrapyramidal symptoms. The 52 group had shorter length of stay (13.8 vs. 17 h; p = 0.03), lower incidence of hypotension (7 vs. 32 patients; p < 0.001), and oxygen desaturation (0 vs. 6 patients; p = 0.01), and fewer physical restraints (53 vs. 86 patients; p = 0.001) compared with the B52 group. Conclusions: Both the B52 and 52 combinations infrequently required repeat agitation medication; however, the B52 combination resulted in more oxygen desaturation, hypotension, physical restraint use, and longer length of stay.