Etizolam Blood Concentrations in 191 Forensic Cases in Ontario, Canada (2019-2020).

Although not used clinically in North America, etizolam has been identified in forensic samples as an illicit 'designer' benzodiazepine. As a central nervous system depressant, analysis for etizolam has probative value in both death investigations and forensic cases where incapacitation or human psychomotor performance is relevant. This report examines toxicological findings and demographic data in a series of authentic forensic cases analyzed between November 2019 and December 2020 in which etizolam was quantified by liquid chromatography-tandem mass spectrometry analysis. Blood concentrations were determined in 191 individuals aged 1-75 years. In living individuals (i.e., impaired driving and sexual assaults), etizolam concentrations ranged from <5 to 767 ng/mL which overlapped with the range of <5 to 260 ng/mL reported in death investigations. In all but one case, other drugs were detected in combination with etizolam. Fentanyl was the most common co-occurring drug and was present in 164 cases (86%). Additional case details are provided for cases of forensic interest: two deaths involving children <3 years of age, two deaths involving body packing and an individual arrested for drug-impaired driving with, to our knowledge, the highest reported etizolam concentration to date.