Characteristics and circumstances of death related to the self-administration of ketamine

Background and aims: Ketamine is used for anaesthesia, sedation and the treatment of mood disorders, but is also widely used for non-medical purposes. This study aimed to: (1) determine the characteristics and circumstances of all recorded cases of self-administered ketamine-related death in Australia, 2000–19 and (2) determine the toxicology and major organ pathology of cases. Design: Retrospective study of all Australian cases in which self-administered ketamine was a mechanism contributory to death, retrieved from the National Coronial Information System. Setting: Australia-wide. Cases: Sixty-eight cases, with a mean age of 35.2 years (standard deviation = 11.5, range = 16–63), 76.5% male. Measurements: Information was collected on cause of death, demographics, circumstances of death, toxicology and major organ pathology. Findings: Death was attributed to toxicity in 82.3% of cases (accidental, 58.8%; deliberate, 23.5%), suicide by violent means (8.8%) and traumatic accident (8.8%). In six cases the decedent had been prescribed ketamine. In 32.4% the final route of ketamine administration was by injection. The fatal incident predominantly occurred in a private environment (72.1%). Ketamine was present in the blood of 90.1% and other biomarkers in the remainder. The median blood ketamine concentration was 0.2 mg/l (0.02–6.9 mg/l). Other drugs were detected in 95.5% of cases: opioids (59.1%), hypnosedatives (57.6%), psychostimulants (50.0%), alcohol (27.3%), Δ-9-tetrahydrocannabinol (18.2%), antidepressants (28.8%) and antipsychotics (9.1%). Pulmonary oedema was present in 82.2% of cases that underwent autopsy and pneumonia in 26.7%. Conclusions: The typical case of self-administered ketamine-related death in Australia, 2000–19, was a male in his mid-30s who had used multiple drugs, with the fatal incident most commonly occurring in a private setting. Death due to accidental drug toxicity was the most common manner of death, but suicide was highly prevalent.