Changes over time in novel benzodiazepines contributing to fatal overdoses in Victoria, Australia

Novel benzodiazepines (NBZN) have increased in availability and use since the mid-2000s, with a corresponding rise in associated harms including deaths.

The study used data from the Victorian Overdose Deaths Register to explore which specific NBZNs and combinations of NBZNs contributed over time to Victorian overdose deaths between January 2009 and December 2023.

There were 140 NBZN-involved overdose deaths in Victoria, with an observable increase in deaths from 2019 onward. Eight main groupings of deaths in time were identified, based on contributing NBZNs. Key groupings included etizolam-related deaths between 2019 and 2021, followed by flualprazolam and clonazolam deaths, and later, bromazolam and clobromazolam combinations in 2022-2023.

These findings reflect the transiency of NBZNs in Victoria's unregulated drug market and highlight the importance of certain harm reduction measures in addressing increasing NBZN use. These include public education around the risks of using benzodiazepines not dispensed from pharmacies and the use of drug checking services to assist people obtaining benzodiazepines from unregulated drug markets.