Inter-Year Comparison of Adverse Reactions Associated with Legal Cannabis Products Reported to Health Canada, 2018-2019 to 2021: An International Journal of Medical Toxicology and Drug Experience

ABSTRACT

Introduction: Since the legalization of cannabis for non-medical purposes in Canada on October 17, 2018, there have been changes in the landscape including increasing availability of legal cannabis products, ongoing public knowledge and education on cannabis, an outbreak of vaping-associated lung illness and the covid-19 pandemic. These shifting contexts may have influenced cannabis use behaviours, and the number and type of cannabis adverse reactions (ARs) reported since legalization. Health Canada's (HC) Vigilance Framework for Cannabis Products allows for the monitoring, detection, assessment and risk management of ARs to support regulatory decision-making, knowledge translation and public communication of the safety of cannabis products. Objective: The objective of this presentation is to provide an inter- year comparison of ARs associated with legal cannabis products reported to HC during the first year (October 17, 2018-December 31, 2019), second year (January 1, 2020-December 31, 2020) and third year (January 1, 2021-December 31, 2021) of legalization. Methods: A descriptive, comparative analysis of AR cases involving legal cannabis products received by HC from October 17, 2018 to December 31, 2019 (referred to as 2018-2019), January 1, 2020 to December 31, 2020 and January 1, 2021-December 31, 2021 was conducted to characterize ARs across these three reporting periods. Results: The total number of cases received by HC increased across reporting periods (n = 151 in 2018-2019, n = 161 in 2020, n = 174 in 2021), with serious cases increasing 36% overall between 2018-2019 and 2021 despite 2018-2019 having covered a longer reporting per- iod. Cases more frequently involved females than males in all periods, while AR cases in 2020 and 2021 more frequently involved older adults (65+ years), whereas middle age adults (35 to 64 years) accounted for the largest proportion of cases in 2018-2019. Ingestible cannabis extracts (e.g., cannabis oils in liquid or capsules) were the most frequently reported suspect cannabis product in AR cases across three reporting periods despite widening availability of other types of legal cannabis products (cannabis topicals, other extracts such as cannabis vaping products and edibles) as of October 17, 2019. Conclusion: While the total number of cases of ARs associated with legal cannabis products submitted to HC have increased across reporting periods, other variables have remained stable or have decreased. Health Canada will continue to monitor and analyse trends in cannabis ARs and publish these results in future years.