BACKGROUND AND AIMS Mortality rates among people who use heroin are estimated to be 15 times that of the general population. The study aimed to determine (1) the case characteristics and circumstances of death of heroin-related toxicity deaths in Australia, 2020-2022; (2) their toxicological profile and major autopsy findings; (3) the proportion of cases in which blood 6-acetyl morphine (6AM) was detected, as a proxy measure of survival times; and (4) compare 6AM positive and negative cases on toxicology, circumstances of death and acute clinical presentation.

DESIGN Retrospective study of heroin toxicity deaths in Australia, 2020-2022, retrieved from the National Coronial Information System.

SETTING This study was conducted Australia-wide.

CASES There were 610 cases of fatal heroin-related drug toxicity.

MEASUREMENTS Information was collected on characteristics, manner of death, toxicology and autopsy results.

FINDINGS The mean age was 42.6 years (range 18-73 years), 80.5% were male and 7.5% were enrolled in a drug treatment programme. The circumstances of death were as follows: unintentional drug toxicity (86.2%), combined unintentional drug toxicity/disease (11.3%) and intentional drug toxicity (2.5%). The median free morphine concentration was 0.17 mg/L (range 0.00-4.20 mg/L). Psychoactive drugs other than heroin were present in 95.2% (Confidence Interval 93.1%-96.8%), most commonly hypnosedatives (62.3%, 58.2%-66.4%) and psychostimulants (44.8%, 40.7%-49.1%). Major autopsy findings of clinical significance included acute bronchopneumonia (14.8%, 11.3%-18.8%), emphysema (16.9%, 13.2%-21.1%), cardiomegaly (30.1%, 12.7%-28.2%), coronary artery disease (27.4%, 23.0%-32.3%), coronary replacement fibrosis (13.4%, 10.1%-17.3%), hepatic cirrhosis (8.8%, 6.6%-12.2%) and renal fibrosis (10.3%, 7.3%-14.0%). In 47.0% (42.3%-51.2%), 6AM was present in blood.

CONCLUSIONS The 'typical' heroin overdose case in Australia from 2020 to 2022 was a male who injected heroin, aged in the 40s, not enrolled in a treatment programme and had used multiple drugs. In over half of cases, there had been a sufficient survival time for 6-acetyl morphine to have been metabolised, which may indicate times in excess of 20-30 min.