One potential harm of increased access to cannabis is poisoning. It is widely believed that cannabis is safe in overdose,^{3 but it can cause central nervous system (CNS) excitation, CNS depression, hallucinations, psychosis, and cardiac dysrhythmias.4 The risk of severe toxicity is greater for children, in whom it can lead to apnoea and coma; in one United States study, 32 of 60 children (0–10 years) hospitalised with cannabis intoxication required intensive care.5 Several studies have reported increases in the number of poisonings following medicinal and recreational cannabis legalisation, particularly in children.6 Edibles are particularly high risk products because of their palatability and the possibility of large ingestions.2 Most reports on this problem are from North America.6}

In Australia, the medicinal use of cannabidiol (CBD) was legalised in June 2015, and that of cannabis and tetrahydrocannabinol (THC) in November 2016.^{7 We therefore evaluated recent cannabis poisoning exposures in Australia, stratified by ingestion intent, age group, and product type. We analysed data from the New South Wales Poisons Information Centre (NSWPIC), which receives about 50% of all calls to Australian poisons information centres; 65% of calls are from within NSW, 35% from other states.8 We extracted data on demographic and exposure characteristics, patient disposition, and cannabinoid product types for calls during 1 July 2014 – 30 June 2024. We calculated crude and age-adjusted population exposure call rates (Supporting Information, supplementary methods), and used Joinpoint regression (version 4.9.0.1) to estimate annual percentage changes (APCs) in age-adjusted rates and to detect trend change points. The study was approved by the Sydney Children's Hospitals Network Human Research Ethics Committee (2021/ETH00165).}

There were 3796 calls about cannabis poisoning exposures (2039 regarding exposures of boys or men, 54%) during 2014–24. The exposed person exhibited symptoms of poisoning at the time of the call in 3184 cases (84% of calls); 2783 people (74%) were in hospital at the time of the call or were referred to hospital (Supporting Information, table 1). The number of calls increased during 2014–24 by 12.8% per year (95% confidence interval [CI], 10.3–15.4% per year), and no trend change points were detected (Box 1). Intentional cannabis exposures were reported by 2981 calls (79% of calls), and the number increased by 9.2% (95% CI, 6.3–12.2%) per year. Unintentional cannabis exposures were re

The age-adjusted cannabis poisoning exposure rate was highest for adolescents (15–19 years; 11.4 calls per 100 000 population per year); the age-adjusted rate for unintentional exposures was highest for toddlers (1–4 years; 1.9 calls per 100 000 population per year) (Supporting Information, table 2).

We found that the number of cannabis poisonings reported increased significantly in Australia during 2014–24, particularly exposures of children and adolescents. The reported number of exposures to edibles, which pose a particular risk for young children,^{13 has increased. Our findings are relevant to discussions of increasing access to medicinal cannabis and legalising its recreational use. Lessons learned overseas with different legislative models could be applied in Australia. For example, the sale of edibles is not permitted in some Canadian provinces, and significantly more children are hospitalised with cannabis intoxication in provinces where they are sold.2 While using orally ingested cannabis forms may be less harmful in the long term than smoking cannabis, the acute poisoning risk posed by edible forms of cannabis must be considered. Particular caution needs to be applied to confectionery forms that are attractive for children.}

(For complete research - Source: The Medical Journal of Australia 2025)