"The current trend towards the use of high potent synthetic opioids, especially fentanyl, has caused an extreme increase in the prevalence of non-fatal and fatal overdose events [13, 14]. However, the trend towards higher opioid potency is still ongoing, with several analogues and novel opioids becoming increasingly available. Particularly carfentanil, an analgesic used in veterinary medicine to anesthetise elephants, provides reason for concern. It is estimated to be around 10’000 times more potent than morphine. In 2021, 8% of all illicit drug toxicity deaths in British Columbia (BC) Canada involved this agent [14, 15]. Furthermore, benzimidazole opioids or “nitazenes” emerged in North America and have since gained a foothold in its drug street markets [16, 17]. Nitazenes and their analogues can exceed the potency of fentanyl by a factor of ten and their availability is steadily increasing [18]. For example, isotonitazene was identified in Canadian drug seizures 12 times in 2019, a number that increased to 288 times in 2021 [19]."


Meyer M, Westenberg JN, Jang KL, et al. Shifting drug markets in North America - a global crisis in the making?. Int J Ment Health Syst. 2023;17(1):36. Published 2023 Oct 25. doi:10.1186/s13033-023-00601-x