<em>In vitro</em>, <em>in vivo</em> metabolism and quantification of the novel synthetic opioid N-piperidinyl etonitazene (etonitazepipne)

CONCLUSIONS: Considering small traces of the parent drug often found in real cases, the identification of metabolic biomarkers is crucial to identify exposure to this drug. O-deethylated, oxidated metabolites, and combination thereof are proposed as urinary biomarkers along with the parent …