Flualprazolam distribution in postmortem samples

Fentanyl concentrations in ligated femoral blood in the presence and absence of NPS benzodiazepine drugs. A review of over 1250 benzo-dope / fentanyl toxicity cases in Alberta, Canada

The drug combination referred to as 'benzo dope' has become prevalent in recent years, with an increasing number of fentanyl-related deaths reporting the concomitant presence of one or more benzodiazepine drug, such as etizolam, flualprazolam and flubromazepam. The central nervous system (CNS) depressant effects of these benzodiazepine drugs can exacerbate respiratory and CNS depressant effects resulting from the use/misuse of potent opioids such as fentanyl. This combined and enhanced drug-induced toxicity can pose a significant threat to life. Over a three-year period (2020-2022), the Office of the Chief Medical Examiner, Edmonton, Alberta, Canada issued 2812 case reports with fentanyl detected; of these cases, approximately 45% (1261) were positive for at least one benzodiazepine drug. This study presents concentrations of both fentanyl and benzodiazepine drugs in post mortem blood collected from a visualized, ligated femoral vein. The study demonstrates that the blood concentration of fentanyl in benzo-dope case reports is considerably higher than in cases where no benzodiazepine drug was detected.The median concentration of fentanyl in femoral blood for cases that also contained a benzodiazepine drug was 12.4 ng/mL (2020), 11.9 ng/mL (2021) and 14.0 ng/mL (2022). The median concentration of fentanyl in femoral blood for cases that did not contain a benzodiazepine drug was 8.5 ng/mL (2020), 7.0 ng/mL (2021) and 7.2 ng/mL (2022). The percent differences between the groups were similar with those observed from quantitative analysis of drug powders from unrelated police seizures in Alberta, Canada, suggesting the observed differences in blood fentanyl concentration may be due to the use of a drug substance with a higher concentration of fentanyl.Furthermore, the reported concentration of the benzodiazepine drug(s) is low, such that the role/contribution, if any, that this drug may have played in the decedents' death should be questioned and carefully considered by the certifying medical examiner/coroner.

Evidence of the emergence of illicit benzodiazepines from online drug forums

Illicit or 'designer' benzodiazepines are a growing contributor to overdose deaths. We employed natural language processing (NLP) to study benzodiazepine mentions over 10 years on 270 online drug forums (subreddits) on Reddit. Using NLP, we automatically detected mentions of illicit and prescription benzodiazepines, including their misspellings and non-standard names, grouping relative mentions by quarter. On a collection of 17 861 755 posts between 2012 and 2021, we searched for 26 benzodiazepines (8 prescription; 18 illicit), detecting 173 275 mentions. The rate of posts about both prescription and illicit benzodiazepines increased consistently with increases in deaths involving both drug classes, illustrating the utility of surveillance via Reddit.