Cannabis poisonings among children increasing

As access to medicinal cannabis in Australia increases, so too does the risk of poisoning, especially in adolescents and small children.

A research letter published in the Medical Journal of Australia has examined the rise of cannabis poisoning in Australia since the legalisation of medicinal cannabis.

Medicinal use of cannabidiol (CBD) was legalised in Australia in June 2015, while use of cannabis and tetrahydrocannabinol (THC) was legalised in November 2016.

As access to cannabis increases, so too does the potential harm for cannabis poisoning.

“It is widely believed that cannabis is safe in overdose, but it can cause central nervous system (CNS) excitation, CNS depression, hallucinations, psychosis and cardiac dysrhythmias,” Dr Rose Cairns and her co-authors from the University of Sydney wrote.

Children are especially at risk of severe toxicity, which can lead to apnoea and coma.

“Several studies have reported increases in the number of poisonings following medicinal and recreational cannabis legalisation, particularly in children,” the authors wrote.

Increasing calls to the NSW Poisons Information Centre

The research letter authors analysed data from the New South Wales Poisons Information Centre regarding cannabis poisoning exposures between 1 July 2014 and 30 June 2024.

There were 3796 calls about cannabis poisoning during the period analysed, with the number of calls increasing by 12.8% each year.

The increase in calls isn’t entirely related to legalisation, as the authors noted no trend change points during the reschedule of medicinal-use products during 2015–2016. The authors also noted that a 2019 survey found that only 3.9% of Australians using medicinal cannabis obtained it via prescription.

“The increase in exposure calls could therefore reflect a steady increase in cannabis use during 2014–24 because of changing social norms and perceptions of cannabis safety and legality,” the authors wrote.

Intentional cannabis use was reported in 79% of calls, while 21% of calls related to unintentional cannabis exposure. The age-adjusted cannabis poisoning exposure rate was highest for adolescents, and rates of unintentional exposure were highest for toddlers.

Unintentional exposure most frequently involved concentrates (39%), plant-based cannabis (37%) and edibles (21%), with calls about exposure to edibles increasing rapidly since 2019.

“The more rapid increase in calls about exposures in young people could reflect the increasing availability of edible forms, which can be medically prescribed or obtained illicitly,” the authors wrote.

Edibles pose risk to small children

The rise of poisoning in adolescents and small children is concerning.

“Edibles are particularly high risk products because of their palatability and the possibility of large ingestions,” the authors wrote.

The authors hope that their findings will contribute to discussions relating to medicinal cannabis access and recreational legalisation.

“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.”

While the authors noted that orally ingested cannabis may be less harmful in the long term than smoking cannabis, the poisoning risks posed by edible cannabis cannot be ignored.

“Particular caution needs to be applied to confectionery forms that are attractive for children,” the authors concluded.

Read the research letter in the Medical Journal of Australia.

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