BackgroundAntipsychotic medications are commonly prescribed to critically ill adult patients and initiation of new antipsychotic prescriptions in the intensive care unit (ICU) increases the proportion of patients discharged home on antipsychotics. Critically ill adult patients are also frequently exposed to multiple psychoactive medications during ICU admission and hospitalization including benzodiazepines and opioid medications which may increase the risk of psychoactive polypharmacy following hospital discharge. The associated impact on health resource utilization and risk of new benzodiazepine and opioid prescriptions is unknown.Research questionWhat is the burden of health resource utilization and odds of new prescriptions of benzodiazepines and opioids up to 1-year post-hospital discharge in critically ill patients with new antipsychotic prescriptions at hospital discharge?Study design & methodsWe completed a multi-center, propensity-score matched retrospective cohort study of critically ill adult patients. The primary exposure was administration of ≥1 dose of an antipsychotic while the patient was admitted in the ICU and ward with continuation at hospital discharge and a filled outpatient prescription within 1-year following hospital discharge. The control group was defined as no doses of antipsychotics administered in the ICU and hospital ward and no filled outpatient prescriptions for antipsychotics within 1-year following hospital discharge. The primary outcome was health resource utilization (72-hour ICU readmission, 30-day hospital readmission, 30-day emergency room visitation, 30-day mortality). Secondary outcomes were administration of benzodiazepines and/or opioids in-hospital and following hospital discharge in patients receiving antipsychotics.Results1,388 propensity-score matched patients were included who did and did not receive antipsychotics in ICU and survived to hospital discharge. New antipsychotic prescriptions were not associated with increased health resource utilization or 30-day mortality following hospital discharge. There was increased odds of new prescriptions of benzodiazepines (adjusted odds ratio [aOR] 1.61 [95%CI 1.19–2.19]) and opioids (aOR 1.82 [95%CI 1.38–2.40]) up to 1-year following hospital discharge in patients continuing antipsychotics at hospital discharge.InterpretationNew antipsychotic prescriptions at hospital discharge are significantly associated with additional prescriptions of benzodiazepines and opioids in-hospital and up to 1-year following hospital discharge.