Characteristics of fatal 'novel' benzodiazepine toxicity in Australia

  • Forensic Sci Int. 2022 Feb:331:111140. doi: 10.1016/j.forsciint.2021.111140.
Shane Darke  1 ,  Amy Peacock  2 ,  Johan Duflou  3 ,  Michael Farrell  2 ,  Julia Lappin  4
Affiliations
  • 1. National Drug & Alcohol Research Centre, University of New South Wales, NSW, Australia. Electronic address: [email protected].
  • 2. National Drug & Alcohol Research Centre, University of New South Wales, NSW, Australia.
  • 3. National Drug & Alcohol Research Centre, University of New South Wales, NSW, Australia; Sydney Medical School, University of Sydney, NSW, Australia.
  • 4. National Drug & Alcohol Research Centre, University of New South Wales, NSW, Australia; School of Psychiatry, University of New South Wales, NSW, Australia.
PMID: 34894611 DOI: 10.1016/j.forsciint.2021.111140
Abstract

Introduction: The study aimed to determine: 1. The characteristics of all recorded cases of fatal drug poisoning involving 'novel' benzodiazepines (NBZDs) in Australia; 2. The toxicology of cases; and 3. The major autopsy findings.

Methods: Retrospective study of all deaths due to drug toxicity in Australia in which NBZDs were present in blood toxicology, retrieved from the National Coronial Information System (2000-2021). Information was collected on case characteristics, toxicology and major organ pathology.

Results: A total of 40 cases were identified, the first occurring in 2015, with a median age of 26.5 years and 87.5% being male. Death was due to accidental toxicity in 92.5% of cases. There were extensive histories of substance use problems (80.0%) and mental health problems (32.5%). Etizolam was the most common NBZD (87.5%), followed by flubromazolam (15.0%), with Other NBZDs detected in 20.0% (delorazepam, diclazepam, flualprazolam, flubromazepam, lormetazepam). Multiple NBZDs were present in 27.5%. Other drugs were present in 97.5%, most commonly opioids (70.0%), registered benzodiazepines (62.5%), psychostimulants (45.0%) and gabapentinoids (32.5%). A CNS depressant Other than a NBZD was detected in 95.0% (n = 38). Autopsies were conducted and available for 30 cases, with pulmonary oedema (76.7%, n = 23), aspiration of vomitus (46.7%, n = 14) and acute bronchopneumonia (36.7%, n = 11) the most common diagnoses.

Conclusions: The 'typical' NBZD-related death was a young male who died due to accidental toxicity. Deaths most frequently involved etizolam and multiple substances, particularly depressants.

Keywords
Benzodiazepines; Etizolam; Mortality; Pathology; Toxicity; Toxicology.
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