Fluorofentanyl and Novel Synthetic Opioids in Accidental Overdose Deaths.

One of the quickest-growing subclasses of novel psychoactive substances is novel synthetic opioids (NSO), which are categorized as fentanyl analogs (fentalogs) or non-fentanyl opioids that bind to the mu-opioid receptor. Increased detections of NSO have been observed in the United States. However, limited information on their prevalence outside of the East Coast is available. This study details the prevalence of NSO, specifically fluorofentanyl, in the biological and drug paraphernalia specimens of accidental overdose deaths in San Francisco in 2022. A recently developed and validated LC-MS-MS method was utilized for the analysis of over 250 NSO. Out of the 649 accidental overdose deaths in 2022, 617 cases were available for blood analysis, with at least one NSO detected in 48 cases (7.8%). Fentalogs were detected in all 48 cases, with fluorofentanyl being detected in 40 cases. In postmortem femoral blood, estimated concentrations of fluorofentanyl ranged from 0.1 to 8.9 ng/mL, and 0.05 to 85 ng/mL in urine. Polysubstance use with NSO was seen with fentanyl (89.6%), methamphetamine (70.8%), cocaine (33.3%), and heroin (18.8%). NSO, mainly, fluorofentanyl were observed in matched drug paraphernalia. This report documents the migration of fluorofentanyl to the West Coast, specifically California.