Increased risk of non-fatal overdose associated with NPS-type [‘street’] benzodiazepine use in Scotland, UK

Background: Drug-related deaths (DRDs) in Scotland increased for seven years in a row between 2014 and 2020, consolidating Scotland’s place at the top of the United Kingdom and European drug-related mortality charts. One of the defining features of this recent and rapid rise has been the role of benzodiazepines, which are now involved in two-thirds of all DRDs. The majority of these deaths are linked to use of NPS-type benzodiazepines [‘street-benzos’]. NPS-type benzodiazepines have been identifed by the United Nations as a global threat to public health.This study aimed to estimate the prevalence and determinants of street-benzo use and related harms among a national sample of people who inject drugs (PWID).

Methods: Data from the 2019-20 Needle Exchange Surveillance Initiative (NESI) was analysed using logistic regression. NESI is a voluntary, anonymous, biennial, cross-sectional, bio-behavioural survey of PWID attending community-based services providing injecting equipment in mainland Scotland.

Results: Prevalence of street-benzo use in the past six months among PWID in Scotland in 2019-20 was 52% (1259/2436) and significantly associated with age (aOR 0.97, 0.96-0.98), frequent incarceration (aOR 1.32, 1.09-1.60), recent public injecting (aOR 3.65, 2.68-4.97), a recent OAT prescription (aOR 1.89, 1.52- 2.34), and a history of benzodiazepine prescription (aOR 1.89, 1.45-2.48). In addition, street-benzo use was significantly associated with non-fatal overdose in the past year among PWID (aOR 2.48, 1.91-3.22).

Conclusion: This study found a high prevalence of street-benzo use among PWID in Scotland, especially among populations at high risk of drug-related death, and an association between street-benzo use and increased risk of non-fatal overdose. These novel findings highlight the scale of the street-benzo issue Scotland faces and the urgency required to expand its harm reduction infrastructure to address this unique element of the overdose crisis.