Reports of novel non-fentanyl synthetic opioids (i.e. benzimidazole-opioids group) in the drug supply are emerging in Ontario, British Columbia and internationally. In addition, increasing opioid-related deaths over the past several decades have escalated to unprecedented levels during the COVID-19 pandemic. Given the need for effective responses of the health system to reduce substance-related harms, it is important to consider the potential impact of novel non-fentanyl synthetic opioids on opioid-related morbidity and mortality in Ontario. While there are other groups of NSO, this review and risk assessment focus specifically on the benzimidazole-opioids group. 

Key messages:

• Novel non-fentanyl synthetic opioids (NSOs) in the benzimidazole-opioids group (e.g., isotonitazene, metonitazene, etonitazene; also known as “nitazenes”) have emerging presence in the unregulated drug supply, including samples from communities and deaths in Ontario.
• There is uncertainty in characterizing the specific risk of benzimidazole-opioids in Ontario due to the small body of relevant information, testing limitations, and overall volatility and toxicity of the unregulated drug supply (e.g., fentanyl/analogues, benzodiazepines and other novel psychoactive substances (NPS).
• The risk of severe overdose with benzimidazole-opioids is moderate to high, with the potential to need higher doses of naloxone due to potency that may exceed fentanyl and co-occurrence with fentanyl/analogues. The presence of benzimidazole-opioids increases the need for testing and surveillance capacity in harm reduction, health and forensic settings.
• At this time, the available information supports continuing with current approaches to opioid overdose prevention and response, including not using drugs while alone, accessing drug checking and supervised consumption services where available, monitoring respiratory status after using, the use of naloxone if needed, and seeking emergency health care.
• As NSO/NPS continue to emerge, new and innovative public health approaches and communityled responses are needed to address the toxic drug supply to improve drug policy and safety for people who use drugs. 

See also, webinar recording, October 2021, Learning exchange: Risk of novel synthetic opioids in Ontario and link to webinar slides. (1.30 hours)