Retrospective analysis of low-dose versus higher-dose haloperidol in older emergency department patients.

Background: A reduced initial dose of injectable haloperidol is recommended in older patients for treatment of acute agitation based on limited studies.

Objective: Assess the effectiveness and safety of higher-dose versus low-dose injectable haloperidol in older patients presenting to the emergency department (ED).

Methods: This was a retrospective, propensity-score matched, cohort analysis conducted at a two-campus healthcare system. Patients ≥65 years old administered injectable haloperidol in the ED were classified as receiving low-dose (≤ 0.5 mg) or higher-dose (> 0.5 mg) haloperidol. Exclusion criteria included acute alcohol withdrawal; ED or hospital stay shorter than four hours; and any of the following before injectable haloperidol administration: safety watch, physical restraint requirement, and administration of oral haloperidol, other acute antipsychotics, or benzodiazepines. The primary outcome was composite treatment failure, defined as need for repeat injectable haloperidol, alternative sedative, restraints, or safety watch within four hours of haloperidol administration. Secondary safety outcomes included escalation of respiratory support, extrapyramidal symptoms, falls, and hospital admission.

Results: Sixty-nine patients per group were matched. There was no statistically significant difference in composite treatment failure (P = 0.087). However, patients in the higher-dose group were more likely to require alternative sedatives (P = 0.035). There were no significant differences between groups for any safety outcomes.

Conclusion: This study suggests low-dose (≤ 0.5 mg) injectable haloperidol may be at least as safe and effective as higher doses (> 0.5 mg) in agitated older adults. Low-dose injectable haloperidol may be preferred in mild to moderately agitated older adults, reserving higher doses for severe agitation.