December 10, 2021
New Synthetic Opioid Protonitazene Increasing in Prevalence as “Nitazenes” Gain Traction Across the United States and Canada
Protonitazene is a new, potent synthetic opioid bearing structural resemblance to etonitazene, a synthetic opioid that is nationally and internationally controlled. Protonitazene is dissimilar in structure to synthetic opioids typically encountered in forensic casework (e.g., fentanyl, heroin); however, protonitazene is a structural isomer of isotonitazene, requiring increased analytical specificity during toxicological analysis. In vitro pharmacological data suggest that this new opioid exhibits potency similar to other recently emergent “nitazene” opioids, and is approximately three times more potent than fentanyl. Protonitazene was first reported by NPS Discovery in May 2021 following initial detection in a toxicology case. To date, nine blood specimens associated with postmortem death investigations in the U.S. were confirmed to contain protonitazene; however, at least six additional cases have been discovered through toxicological surveillance by NPS Discovery as of December 2021. Identifications of protonitazene have also been reported from organizations in Europe. The toxicity of protonitazene has not been examined or reported but recent association with death among people who use drugs leads professionals to believe this synthetic opioid retains the potential to cause widespread harm and is of public health concern.