LAUSR

BACKGROUND AND AIMS Although the prevalence of gamma- hydroxybutyrate (GHB) use is relatively low globally, harms related to the drug appear to be increasing. Few existing studies present reliable, representative, population-level data on GHB-related harms. The aim of this study was to investigate trends in acute GHB-related harms within an ambulance database in Australia. DESIGN, SETTING AND PARTICIPANTS Cross-sectional, retrospective analysis of data on all GHB-related ambulance attendances in the state of Victoria, Australia over a seven-year period (January 2012 - December 2018) MEASUREMENTS: Presentations were characterised based on patient demographics, transport to hospital, co-occurring substance use (i.e. GHB only, alcohol, methamphetamine, heroin, benzodiazepine, and cannabis), and clinical presentation (e.g. symptoms of anxiety, psychosis, depression). FINDINGS There were 5,866 GHB-related ambulance attendances between 2012-2018, with prevalence rate increasing from 8.8 per 100,000 population in 2012 to a maximum of 21.7 per 100,000 population in 2017. Methamphetamine (OR 6.23, p<0.001) and benzodiazepine-related (OR 1.43, p<0.001) co-occurrences; ages between 18-29 (OR 6.58, p<0.001) and 30-39 (OR 2.02, p<0.001); and male gender (OR 1.23, p<0.001) were significant predictors of GHB-related attendances. CONCLUSIONS There has been a 147% increase in the prevalence of gamma- hydroxybutyrate (GHB)-related ambulance attendances in Victoria, Australia between 2012 and 2019, largely attributable to a growth in the proportions of people using GHB alone or concurrently with methamphetamine.