​CFSRE’s NPS Discovery is an open-access drug early warning system (EWS) operating in the United States. This New Drug Monograph, produced in collaboration with Cayman, documents the first report of N-Propionitrile Chlorphine, a novel synthetic opioid bearing structural similarity to other "orphine" benzimidazolones (e.g., brorphine, chlorphine, fluorphine). N-Propionitrile chlorphine was first identified by the CFSRE in August 2024 and was confirmed using Cayman's reference standard.