Weight is a factor that influences the dosages of many medications, although no clinical studies have evaluated this factor in the use of agitation medications in the obese population. The objectives of this study were to assess the need for weight considerations in dosing antipsychotics and benzodiazepines for patients with agitation and to assess prescribing patterns in agitated patients.
This retrospective cohort study compared outcomes between obese and nonobese adult patients who received at least one parenteral administration of an antipsychotic or benzodiazepine for agitation in the emergency department. The primary outcomes were total antipsychotic and benzodiazepine doses within 24 hours (in chlorpromazine equivalents and lorazepam equivalents, respectively). Key secondary outcomes included antipsychotic and benzodiazepine doses used for first administration, incidence of repeat emergency medication administration within 24 hours, time to next administration, and number of repeat administrations within 24 hours.
The study examined 115 patient encounters in each cohort of patients in the study. The baseline characteristics of the 2 study cohorts were similar. Both groups had similar mean 24-hour antipsychotic usage [272.7 chlorpromazine equivalents (nonobese cohort), 313.5 chlorpromazine equivalents (obese cohort); P=0.157] and mean 24-hour benzodiazepine usage [0.9 lorazepam equivalents (both cohorts); P=0.750]. Differences between the study cohorts on all of the secondary outcomes were also not statistically significant (P>0.05).
This study did not find the use of higher dosages of agitation medication in the obese compared with the nonobese population. Future prospective trials, with possible emphasis on individual medications, specific etiologies of agitation, or morbid obesity, are required to confirm this finding or to elucidate potential differences in optimal medication dosages for the obese population.