# Naloxone Use and Outcomes in Prehospital and Emergency Department Care

## TL;DR

The study examines how naloxone is used in prehospital and emergency department settings in Canada and finds that most opioid overdoses are reversed before reaching the hospital, but few patients start opioid agonist therapy afterward.

## Contribution

This study provides local data on naloxone administration and outcomes in prehospital and ED settings, emphasizing the role of first responders and bystanders.

## Key findings

- 83.9% of prehospital naloxone administrations successfully reversed opioid toxicity.
- Only 6.25% of patients were started on or referred for opioid agonist therapy after naloxone administration.
- No significant difference in reversal success was found between single and multiple naloxone doses.

## Abstract

Background

Opioid toxicity remains a major public health concern in Canada, which is driven by potent synthetic opioids such as fentanyl. Naloxone is the antidote for opioid toxicity and can be given in a variety of routes and dosages. Naloxone is administered by bystanders, first responders, emergency medical services (EMS), and emergency physicians. Despite its widespread use, there are limited local data on its administration in the prehospital and emergency department (ED) settings, as well as on its associated outcomes.

Materials and methods

This was a retrospective review study of patients presenting to a tertiary care ED in 2024 who had a discharge diagnostic code “poison narcotics” and received naloxone. Prehospital and ED charts were reviewed to collect demographics, naloxone dose, route, number of doses, reversal success, disposition, and opioid agonist therapy (OAT) initiation and referral. Descriptive statistics were used, and Fisher’s exact test was used to compare outcomes between single and multiple naloxone doses.

Results

Thirty-three patients met the inclusion criteria (mean age 40.4 years; 33.3% female). Naloxone was administered prehospital in 93.9% of cases, with 60.6% receiving naloxone prior to EMS arrival. Prehospital reversal success was 83.9%. EMS administered naloxone to 54.5% of patients at various dosages and routes. Seven patients required naloxone in the ED, and two needed an ICU admission. There were no deaths. Only 6.25% of patients were started on or referred for OAT, none directly following opioid toxicity reversal. There was no significant difference in reversal success or disposition between those who received single versus multiple doses of naloxone.

Conclusions

Most cases were successfully reversed prior to ED arrival, and many were managed by first responders and bystanders, highlighting the importance of public education and access to intranasal naloxone. Low rates of OAT initiation underscore the need to prevent barriers to treatment following an ED visit.