- 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
- 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.