Metonitazene Begins Proliferation as Newest Synthetic Opioid Among Latest Cycle of Non-Fentanyl Related Drugs

Metonitazene is a potent synthetic opioid bearing structural resemblance to etonitazene, a synthetic opioid that is nationally and internationally controlled. Metonitazene was first reported by NPS Discovery after detection in a seized drug powder in July 2020. To date, metonitazene has been identified in eight blood specimens associated with postmortem death investigations in the United States. Metonitazene is dissimilar in structure to other synthetic opioids typically encountered in forensic casework (e.g. fentanyl analogues). Metonitazene and similar analogues (e.g. etonitazene, isotonitazene) were first synthesized and reported in the literature in the 1950s. Pharmacological data suggest that this group of synthetic opioids have potency similar to or greater than fentanyl.