Skip to content

Evidence Brief: Novel Non-Fentanyl Synthetic Opioids: Risk Assessment and Implications for Practice

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.