At this year’s MATT meeting, Stuart Kurtz spoke to attendees about the prevalence of nitazene analogs and the concentrations at which Axis detects them. We have previously discussed what nitazenes are in blog posts (see links below). As a reminder, they are potent mu opioid receptor agonists that behave similarly to fentanyl & its analogs, morphine, heroin, hydrocodone, oxycodone, and other opioids. They are structurally distinct from these drugs and will not be detected using immunoassays designed for these other compounds. Isotonitazene and metonitazene were the first to emerge in 2019-2020.
Metonitazene has remained our most popular analog detected in the areas we service. N-pyrrolidino metonitazene and N-pyrrolidino protonitazene have emerged in the last year with the latter nearly overtaking metonitazene in 2024. Unsurprisingly, fentanyl is the drug most commonly detected with them.
Our method reports quantitative results for butonitazene, etodesnitazene, etonitazene, flunitazene, isotodesnitazene, isotnitazene, metodesnitazene, metonitazene, N-pyrrolidino etonitazene, and protonitazene. Our limit of detection for these is 1.0 ng/mL. Median concentrations of the available quantitative data show a range of 1.5-2.9 ng/mL. A good target for limit of detection for these compounds would be 0.5-1.0 ng/mL. There is no expected therapeutic range and the purity of drugs purchased on the street is highly variable. This can make it hard to determine what the expected blood concentrations should be. Given their potency is similar to fentanyl and its analogs, similar cutoffs to those compounds can be used as a starting point.
Our project presented at AAFS 2025 highlighted that the nitazenes may be highly specific to various regions. Knowledge of seized material in your jurisdiction will tell you whether or not you should be considering nitazenes in otherwise negative toxicology cases. As new compounds emerge, we will remain current on the information available and use it to inform our testing scope. Nitazene Analogs are screened in Axis’ Comprehensive Panel with Analyte Assurance™ (70510) or as a standalone panel (13910) To discuss the potential impact of nitazenes in your casework or for more information about the presentation, please contact [email protected].