Ethylbromazolam, a new designer benzodiazepine, has emerged in Canada, the UK, Australia, and Germany, with increasing detections since November 2024 and a concurrent decrease in bromazolam detections, likely due to bromazolam's international control on December 3, 2024. Other designer benzodiazepines like desalkylgidazepam and clobromazolam have also increased. In vitro patch clamp assays show ethylbromazolam has similar activity at the GABA-A receptor as bromazolam, with EC50 values of 10.1 nM and 15.2 nM respectively, indicating comparable pharmacological activity and potential harm. Ongoing market monitoring is recommended.
New Psychoactive Substances (NPS) are drugs designed to mimic the effects of controlled substances while evading legal regulation, often called 'legal highs.' They include classes such as cannabimimetics, depressants, dissociatives, hallucinogens, opioids, and stimulants. Structural diversity within each class makes detection by standard clinical laboratory tests difficult and complicates result interpretation. This review describes each NPS class, its mechanism of action, common structures, metabolic pathways, and recent examples, with a focus on Canadian drug trends. It also discusses analytical limitations in clinical laboratories and how toxicosurveillance can improve detection of NPS in a rapidly changing landscape.