Optimal Injectable Haloperidol Dose Assessment in the Older Hospitalized Inpatient

Abstract

Background: Haloperidol can be used off-label for agitation and/or delirium in older individuals. The recommended initial intramuscular or intravenous dose is 0.5 to 1 mg. However, the evidence to support these doses is nominal.

Objectives: The primary outcome was to determine whether low-dose injectable haloperidol (≤0.5 mg) was similar in effect to higher doses by assessing the need for repeat doses within 4 hours as a surrogate marker. Secondary outcomes include comparison of length of stay, utilization of restraints, and discharge outcomes between dosage groups.

Methods: This was a retrospective, single-center, cohort study. Patients aged ≥65 years who received haloperidol injectable who were not on antipsychotics prior to admission were reviewed.

Results: In the low-dose group (n = 15), no patients required additional haloperidol doses within 4 hours compared with 1 patient each in the medium-dose (n = 23) and high-dose (n = 19) groups (P = 0.94). There was a difference regarding length of stay, utilization of restraints, and discharge to facility when admitted from home favoring low-dose haloperidol.

Conclusions and relevance: While limited by sample size and retrospective design, patients who received low-dose haloperidol demonstrated similar efficacy to those who received higher doses of haloperidol. In addition, secondary outcomes mentioned above favored the use of low-dose haloperidol as well. Based on these findings, low-dose haloperidol is a reasonable initial dose for the agitated older patient.

Keywords: antipsychotic; antipsychotic-naïve; dose-optimization; geriatric; lowest effective dose.