Protodesnitazene: The identification and tissue distribution of a new nitazene

Abstract

Multiple new analogues from the 2-benzyl benzimidazole or "nitazene" class of drugs have emerged on the drug market in recent years. Nitazenes are highly potent μ-opioid receptor agonists that present a substantial public health concern due to their elevated risk of severe toxicity in overdose and their significant potential for misuse. We report on a case involving an overdose with another new analogue from this class, protodesnitazene. The drug has a similar potency to fentanyl and has not been previously reported in toxicology specimens or drug seizures. Protodesnitazene was initially identified by LC-QTOF-HRMS (High Resolution Mass Spectrometry) and distinguished from relevant isomers by chromatographic separation, with spectral and retention time matching against reference standards. A quantitation method employing solid phase extraction using mixed mode cartridges and utilizing LC-MS/MS operating in MRM mode was developed and partially validated for non-routine analyses. Concentrations for the parent drug were determined in a range of postmortem matrices and femoral blood levels (77-222 ng/mL) were found to be comparable to previously identified desnitazene compounds. Protodesnitazene was observed to metabolize extensively by N-dealkylation, O-dealkylation, and hydroxylation. Glucuronides were not present at high levels in the blood but were prominent in the urine. Protodesnitazene was also identified in an associated seized powder.

The authors' abstract, as published at the source. Journal of Forensic Sciences, 2026 · DOI ↗