Severe toxicity involving N-pyrrolidino etonitazene in the United Kingdom—a case report.

Dear Editor, There have recently been increasing episodes of severe toxicity involving synthetic opioids, especially in North America. While fentanyl and its analogues are commonly involved, there are increasing reports of toxicity from non-fentanyl opioids, including 2-benzylbenzimidazole ("nitazene") compounds, which are structurally unrelated to morphine or fentanyl (Figure 1) [[1]]. Synthesis, chemical characterization, and -opioid receptor activity assessment of the emerging group of "nitazene" 2-benzylbenzimidazole synthetic opioids. [Extracted from the article]