In this episode, I’ll discuss the lowest effective dose of IV or IM haloperidol for elderly hospitalized patients with agitation.
Despite the black box warning that antipsychotics can increase mortality in elderly patients, medications like haloperidol are sometimes needed to control agitation from hospitalized elderly patients that have delirium and associated symptoms of agitation that make them a danger to themselves or staff.
Organizations like the American Geriatrics Society or the American Psychological Association recommend low doses of haloperidol be used, however there is very limited data available on the effectiveness of low doses of haloperidol such as 0.5 mg IV or IM in elderly patients with agitation. This may lead to provider skepticism of interventions by pharmacists designed at using such low doses.
To add to the body of knowledge available on low-dose haloperidol for agitation in elderly patients, a group of authors published in Annals of Pharmacotherapy a retrospective single center cohort study that looked at low, medium, and high doses of parenteral haloperidol in elderly agitated patients.
Shout out to “Pharmacy John” who is a podcast listener and one of the study authors and recently brought this article to my attention.
The center the study took place at has a geriatric dosing guideline that states:
…in antipsychotic-naïve patients, the maximum dose of injectable haloperidol intramuscularly or intravenously is 0.5 mg. If a clinician orders an injectable haloperidol dose of more than 0.5 mg in an antipsychotic-naïve patient, pharmacists contact the ordering provider to discuss dose reduction.
The study looked at nearly 50 elderly patients and split them into 3 cohorts:
The low haloperidol dose group received 0.5 mg or less IM or IV.
The medium haloperidol dose group received more than 0.5 mg and up to 1 mg IM or IV.
The high haloperidol dose group received more than 1 mg IM or IV.
The primary outcome looked at efficacy as judged by the need for repeat doses within 4 hours.
Secondary outcomes were the hospital length of stay, utilization of restraints, and discharge outcomes (to a facility when admitted from home) between dosage groups.
The low, medium, and high dose groups had 15, 23, and 19 patients, respectively.
No patients in the low dose group required a repeat dose within 4 hours and only 1 patient each in the medium and high dose group required a repeat dose.
The low dose group had statistically significant favorable differences in the secondary outcomes of length of stay, need for restraints, and discharge outcome.
The authors discuss pharmacokinetic data that suggests lower doses of haloperidol should achieve higher plasma concentrations in elderly patients.
…this study suggests haloperidol at a low dose of 0.5 mg was sufficient to address the patient’s delirium, agitation, and/or aggression…and…avoiding larger haloperidol doses in the older patient minimizes potential adverse effects from this potent medication while retaining efficacy.
The availability of this data in the medical literature provides support to pharmacists who intervene to lower doses of haloperidol for agitation in elderly patients.
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