Bromazolam Blood Concentrations in Post-mortem Cases - A British Columbia Perspective.

Bromazolam is a designer benzodiazepine that was first detected in British Columbia in January 2021. Post-mortem cases were analysed using a comprehensive blood drug screen by liquid-chromatography high resolution mass spectrometry before being retrospectively analysed with an in-house Novel Psychoactive Substances (NPS) data processing method. Bromazolam was detected in 41 post-mortem cases in 2021 and quantitatively confirmed by standard addition, using liquid chromatography tandem mass spectrometry. The mean bromazolam concentration observed was 11.4 ± 53.7 ng/mL (median concentration: 1.6 ng/mL), with a range from 0.5 to 319.3 ng/mL, and the majority of cases co-occurring with fentanyl. These low concentrations may be indicative of a presumed enhancement of opioid effects rather than being used as a standalone drug. Bromazolam was always detected with opioids (fentanyl, carfentanil), stimulants (methamphetamine) and/or other benzodiazepines (etizolam, flualprazolam). To our knowledge, this is the first report to provide concentrations of bromazolam in post-mortem blood samples in Canada.