The number of opioid overdose cases is increasing in Canada. Although data showing current national-level trends of opioid toxicity-related morbidity and mortality were not identified for this Rapid Response report, the Canadian Institute for Health Information and the Canadian Centre on Substance Abuse have jointly reported that the rate of hospitalizations due to opioid poisoning in Canada increased by more than 30% between 2007–2008 and 2014–2015. Also, data from the Office of the Chief Coroner for Ontario show that the number of opioid overdose-related deaths increased from 206 in 2004 to 624 in 2014.

Naloxone, a drug that can temporarily reverse opioid overdose, is a competitive opioid receptor antagonist with a rapid onset and short duration of action. It has been used to reverse the effects of a variety of natural, semisynthetic, and synthetic opioids in both pre-hospital (community) and hospital settings. Some advantages of using naloxone as a reversal agent for opioid overdose include absence of potential for abuse, a wide dose range without a likelihood of overdose, and a lack of pharmacological activity in the absence of opioids or other opioid antagonists.

Health Canada approved non-prescription use of naloxone for emergency reversal of opioid overdose in pre-hospital settings in March 2016, and authorized the sale for Naloxone Hydrochloride Nasal Spray in Canada on July 5, 2017. Naloxone Hydrochloride Nasal Spray is a needleless device that delivers a fixed intranasal dose of naloxone.9 Other formulations of naloxone, including injectable for intramuscular, intravenous, or subcutaneous use, are available in Canada. Also, atomizer devices have been used in practice to deliver injectable naloxone solution intranasally. Both intranasal and intramuscular naloxone formulations are available for pre-hospital use, including by laypersons in the community.

In 2017, CADTH produced a Rapid Response report summarizing evidence on the comparative clinical effectiveness, cost effectiveness, and evidence-based recommendations for use of the various formulations and delivery mechanisms of naloxone for the treatment of opioid poisoning in pre-hospital settiongs. The evidence available then for that report was limited in number and quality. Therefore, the objective of this current Rapid Response report is to review any new evidence that may have become available since the 2017 report and update the evidence...