759: CHARACTERIZATION OF CONTINUOUS-INFUSION NALOXONE DOSING IN OPIOID OVERDOSE

Abstract

Introduction: Naloxone is a competitive antagonist that is used to reverse the effects of opioid overdose. Due to its short half-life continuous infusions have been indicated in overdose patients. Current recommendations endorse starting naloxone infusions at two-thirds the initial effective dose, however, case reports describe doses ranging from 0.1 mg to 4 mg/hr. The purpose of this medication utilization review is to characterize the utilization and initial dosing of continuous infusion naloxone in adult overdose patients who presented to the emergency department (ED) at a single academic medical center. Methods: This study retrospectively evaluated a cohort of patients 18 years and older who presented to the ED at Virginia Commonwealth University Health and received continuous infusion naloxone for opioid overdose between January 1, 2006, and December 31, 2021. Patients were excluded if the naloxone infusion was not administered, if it was ordered for indications other than opioid overdose, or if the patient required naloxone for iatrogenic overdose. Results: Out of 3056 patient encounters where naloxone was given, only 66 patients were started on a naloxone infusion. On average patients were 46 years old, 65% male, and 73% African American. Heroin was the primary suspected overdose agent in 35% of patients and was unknown in 46% of patients. Seventy-four percent of patients received intravenous naloxone by EMS and 97% received additional naloxone boluses in the ED before starting a continuous infusion. Patients received a median of 3 mg of naloxone as boluses before starting continuous infusion naloxone. Fifty percent of patients were started on naloxone infusions < 2 mg/hr, 39% were started on the institution default of 2 mg/hr, and 11% were started >2 mg/hr with a median infusion rate of 1.5 mg/hr and duration of 7.8 hours. Fifty-four percent of patients who were started on an initial rate of 2 mg/h had an infusion dose decrease before discontinuation, while 31% required a dose increase. Conclusions: Given the current opioid epidemic, the optimal dosing of continuous infusion naloxone is unknown. It is unclear whether the recommendation of two-thirds of initial effective dose is still applicable. Currently, empiric dosing is variable and provider dependent.