More than half of all prescriptions for medicinal cannabis in Australia are written by doctors in Queensland, with prescriptions often given for conditions there is little evidence medicinal cannabis can treat, new research reveals.
Medicinal cannabis products such as capsules, creams, oils, lozenges, sprays and granulated flowers were approved for prescription 159,665 times between the start of Australia’s medicinal cannabis program in February 2016 and September 2021, research led by the University of Sydney’s Lambert Initiative for Cannabinoid Therapeutics shows.
Data obtained through a freedom of information request to drugs regulator the Therapeutic Goods Administration (TGA) revealed the age of those prescribed the drugs, the reason for prescribing, and the state or territory where the prescription was made.
Some of this information has since been made publicly available on the TGA’s Medicinal Cannabis Access Data Dashboard – revealing approved medicinal cannabis prescriptions have now reached more than 247,000 – though the data published is not as detailed as that obtained by the researchers.
The researchers’ analysis found anxiety was the reason given for 16% of medicinal cannabis prescriptions. Flower-based medicinal cannabis prescriptions for anxiety were most common, despite a lack of high-quality clinical studies showing treatments made from the flower of the cannabis plant are effective for the condition.
Pain was the most common reason for medicinal cannabis being prescribed (61% of prescriptions), and 5.7% of prescriptions were for sleep disorders. The data also shows that prior to 2020, people between 45 and 52 years old had the highest incidence of prescriptions. After 2020, those between 20 and 31 years old were the predominant group being prescribed medicinal cannabis.
Queensland was the source of 51% of prescriptions between 2016 and 2021.
The lead author of the study, Sara MacPhail, said it is unclear why the age demographic had changed, or why so many prescriptions were being made in Queensland. These were findings that need further study, she said.
Dr Elizabeth Cairns, a co-author on the paper, said another interesting but unexplained finding was that prescriptions of topical creams containing CBD, a chemical found in cannabis, were being written for convulsions.
“This usage has not been extensively explored,” Cairns said. “We are aware of clinical trials in that space, but not strong evidence.”
The findings were published on Tuesday in the journal Frontiers in Pharmacology. The Royal Australian College of General Practitioners (RACGP) president, Adjunct Prof Karen Prince, said the findings were worrying.
“The quality of evidence varies and in some cases is inconclusive or insufficient to suggest any benefit to patients,” she said.
“The RACGP is also very concerned about the emergence of online prescription services and business models offering medicinal cannabis in Australia, which may be contributing to the nature of prescriptions. There are numerous risks to these ‘on demand’ types of services, including misdiagnosis and missed opportunities for preventative care. They won’t have the patient’s medical history.”
The use of medicinal cannabis to treat pain is controversial in Australia. The Australian Faculty of Pain Medicine suggests cannabinoid products should not be prescribed to treat chronic non-cancer pain, unless the patient is being treated as part of a registered clinical trial so that better evidence can be gathered.
Few studies have been done examining cannabis for the treatment of sleep disorders.
“However, both the medical practitioner and the TGA are involved in the prescription and approval of medicinal cannabis under the special access scheme in Australia, so it’s gone through rounds of approval before going to the patient,” Cairns said.
“So I think medicinal cannabis is often seen as that last resort when other treatments have failed.”
Prof Jennifer Martin, a clinical pharmacologist, physician, and chief investigator with the Australia Centre for Cannabinoid Clinical and Research Excellence, said although doctors may feel they are prescribing as a “last resort”, it can be difficult to say no to a distressed and ill patient.
There could be many barriers to patients trying more evidence-based treatments such as multi-disciplinary pain clinics, psychotherapy or exercise programs, she said.
“Some of those programs take a real investment from the patient to commit to them over time, and often people can’t get into the programs because there’s a waitlist, or due to cost,” Martin said.
She said in New South Wales, the chief health officer, Dr Kerry Chant, had secured government funding for the NSW Cannabis Medicines Advisory Service, which gives advice and evidence-based information to doctors.
“A lot of doctors end up not going ahead with the prescription after getting advice from the service,” Martin said.
“Sometimes the patient was not aware that medicinal cannabis products could worsen their condition. This might also be why prescriptions are lower in NSW than Queensland.”
