Watchdog raises alarm on medicinal cannabis boom

Australia’s drug watchdog has flagged concerns about a boom in cannabis prescriptions and warned that such rapid growth is affecting its ability to limit harm in some patients.

Government data indicates that 291,469 new patients began medical cannabis treatment through authorised prescribers between January and June, up from 3086 three years ago.

The industry grossed about $244 million in revenue in 2022, with revenue growing at 41 per cent from the first half of the year to the second, according to data shared with the industry and viewed by The Age.

Australia’s medical cannabis scheme was set up in 2016. Because there are almost no approved cannabis medicines, the scheme allowed doctors to prescribe the drug through a pathway meant to provide compassionate access – for example, to patients dying of cancer.

According to the Therapeutic Goods Administration (TGA): ‘‘Access of medicinal cannabis products is pushing the boundaries of the intention of these schemes, which is primarily to provide access to goods for use in rare and extenuating circumstances where the patient has exhausted approved and available treatments in Australia ...’’

The agency warned Health Minister Mark Butler of this late last year in a document outlining possible regulatory changes, obtained by The Age under freedom of information.

Applications by GPs to prescribe cannabis are meant to be vetted by health bureaucrats, but so many are coming in, those deemed low risk are now bulk approved, the document states.

It raised concerns about how the drug was being prescribed and whether there was adequate scrutiny over the “risk-benefit” ratio for patients.

‘‘The prolonged therapeutic use of ‘unapproved’ medicinal cannabis products, especially in the vulnerable paediatric population, calls into question the appropriateness of the TGA to continue to place the risk of prescribing of these products with the medical profession whilst an unregulated industry continues to grow ...’’ the document reads.

‘‘There is little scrutiny on whether the risk-benefit ratio remains favourable over time for patients who use them. This concern is especially relevant when it comes to long term use of THC-containing products, especially in children, who are more vulnerable to the deleterious effects of this cannabinoid.’’

The leading reason for prescribing cannabis is to treat pain. Scientists and advocates had long hoped that when proper research was done, cannabis would prove to be a powerful treatment for chronic pain.

Professor Rachelle Buchbinder, a pain researcher based at Monash University who published a review of the data in 2021, said there was now enough evidence to conclude the drug did not work for pain.

‘‘Based on the trial evidence, there is small to very small to no benefit in pain, or in function, or in sleep quality,’’ she said.

‘‘It’s very concerning. And I’m worried about an opioid epidemic just being replaced by a medical cannabis epidemic. This is another commercially driven treatment where the harms are going to be outweighing the benefits.’’

Professor Michael Vagg, dean of the Faculty of Pain Medicine at the Australian and New Zealand College of Anaesthetists, said the cannabis boom was ‘‘ethically more concerning’’ than opioids because at least opioids were shown to be effective in treating pain.

‘‘The cannabinoid use boom that is beginning is much more blatantly commercial than the increase in opioid prescribing,’’ he said. ‘‘It is also ethically concerning that the vast majority of prescribing is for chronic pain, and is being done by non-specialists who have a very narrow focus on pharmaceutical management of pain.’’

Professor Iain McGregor, academic director of the Lambert Initiative for Cannabinoid Therapeutics, strongly disagreed with Vagg and Buchbinder, pointing to selfreported data showing significant quality-of-life improvements.

‘‘Sensory measures of pain may not change that much with cannabis,’’ he said. ‘‘But what does seem to change is people’s ability to get on with and enjoy their lives. And that’s fantastically useful.

‘‘To try to equate medicinal cannabis uptake with the opioid epidemic is grotesque. Opioids kill people. Cannabinoids do not.’’

Because medical cannabis is not an approved medicine, internal TGA documents warn it is unable to police its safety and quality. Internal TGA data tracked 521 adverseevent reports linked to medical cannabis up to February, with 77 requiring hospitalisation and 16 being life-threatening.

The TGA was also notified of four deaths in children using medical cannabis, although ‘‘the deaths appear related to underlying health conditions’’, the documents note.

An analysis of prescription data to mid-2021 by a team of Australian researchers showed a sharp change in prescription patterns from 2019. Before 2019, most prescriptions were for people over the age of 45, and they were mostly prescribed cannabis oils. But after, prescriptions for younger men increased, with data suggesting this group preferred either dried cannabis flower or ‘‘inhalation products’’ – possibly vape cartridges.

Peter Crock, chair of Medicinal Cannabis Industry Australia, said it was clear recreational users were turning to the scheme: ‘‘There’s no doubt there’s an element of that.’’

However, moving users away from illegal products towards purer medical cannabis was a valuable piece of harm minimisation, he said.

Critics of the drug were ‘‘missing the point’’, he said. ‘‘Yes, there isn’t clinical evidence for cannabinoids – because it’s been prohibited.

‘‘It’s a circular argument ... Saying there’s a higher risk from cannabinoids than from opioids is an inappropriate direct comparison.’’

Injured workers are increasingly convincing government insurer WorkSafe to cover the cost of medical cannabis, with 108 workers receiving cannabis subsidies in the past 11 months. A WorkSafe spokeswoman said the insurer ‘‘does not support the use of medicinal cannabis except in exceptional circumstances’’.

A TGA spokesman this month said the ‘‘use of an unapproved therapeutic good for a patient is a clinical decision made at the discretion of the medical practitioner’’.

‘‘The prescriber and their patient take full responsibility for the use of the unapproved product,’’ he said.

‘‘All submissions received under the Special Access Scheme B and Authorised Prescriber scheme for unapproved medicinal cannabis are assessed on a case-by-case basis by a TGA pharmacist.’’

A spokeswoman for Butler declined to say how he had responded to the TGA’s advice. ‘‘The decision to prescribe medicinal cannabis is a clinical decision taken by a patient’s doctor,’’ she said.