Medicinal cannabis blacklisted by Australian pain specialists
Doctors are being told not to use medicinal cannabis to treat patients with chronic pain, warning there is no solid evidence it is effective, as Australia’s medical regulator approves its 100,000th cannabinoid script.
Dean of ANZCA’s pain medicine faculty Professor Michael Vagg. CREDIT:SIMON SCHLUTER The recommendation from the country’s peak pain advisory body to doctors is: “Do not prescribe currently available cannabinoid products to treat chronic non-cancer pain unless part of a registered clinical trial.”
The Faculty of Pain Medicine at the Australian and New Zealand College of Anaesthetists (ANZCA) says there is no robust evidence from gold-standard studies that proves cannabinoid products effectively treat these patients’ suffering. Cannabinoids are the active chemicals in cannabis. But the Therapeutic Goods Administration (TGA) is allowing doctors to apply for special access to prescribe medicinal cannabis products. Proponents argue the substances should be given the benefit of the doubt and offered to patients on compassionate grounds.
Dean of ANZCA’s pain medicine faculty Professor Michael Vagg said medicinal cannabis products on the market “are not even close” to showing they are effective in the management of patients with complex chronic pain.
“The research available is either unsupportive of using cannabinoid products in chronic non-cancer pain or is of such low quality that no valid scientific conclusion can be drawn,” the pain specialist and physician said.
A medicinal cannabis farm at an undisclosed location in NSW that will legally produce large quantities of cannabis oil. CREDIT: JANIE BARRETT Cannabidiol-only formulations have never been the subject of any published randomised controlled trial (which are considered the scientific gold standard).
“Substances like alcohol are more effective pound-for-pound but we don’t have extended opening hours at Dan Murphy’s for pain patients,” Professor Vagg said.
ANZCA released its recommendation on Tuesday as part of the global Choosing Wisely awareness campaign, which highlights treatments, procedures and medications tests that have little or no evidence to support them.
The recommendation has been backed by the International Association for the Study of Pain, the leading global authority on pain research, which released complimentary recommendations on Friday after a comprehensive review of relevant research.
Roughly 190 different cannabis products are now available by prescription via the TGA’s special access application schemes.
TGA boss Professor John Skerritt told attendees at the ACannabis ‘Evolve’ meeting - sponsored by the Medicinal Cannabis Industry Association - last week that the regulator had approved its 100,000th medicinal cannabis application in March. Roughly 64,000 patients have now been prescribed the substances by 2500 prescribers. The vast majority of those applications were for chronic pain such as arthritis, neck or back pain, fibromyalgia and migraines. Anxiety, insomnia and cancer symptoms accounted for just a fraction of medicinal cannabis prescriptions.
Iain McGregor, Professor of Psychopharmacology and Academic director of the Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney agreed the evidence to back its efficacy was “very much under development”.
“But this is a galloping horse heading off into the future with lots of patients already being prescribed medicinal cannabinoids and even more self-medicating,” Professor McGregor said.` “One of the things [ANZCA] has to reconcile is why would all these people continue to use a product that doesn’t help them?
“The TGA conducted its own review which concluded there is some evidence that it works but I agree, we need far more clinical trials in this space to give prescribers more confidence,” he said. Professor McGregor supported a “compassionate approach”. “Let’s give medicinal cannabis the benefit of the doubt while the hundreds of clinical trials around the world build the evidence base for their use,” he said.
But Professor Vagg said the TGA’s analysis took a “very generous” view of the available evidence, while ANZCA’s recommendation was based on a more rigorous interrogation that considered the high risk of bias in some studies.
“The TGA still found about four in 100 chronic pain patients could potentially benefit from medicinal cannabis but 20 to 25 patients would need to stop using it because of the side effects,” Professor Vagg said. ”It is such an amateur mistake to backfill this evidence gap now when this product is already being used. There should have been rigorous work to prove it’s effective and safe and then put it on the market [and continue to monitor its effectiveness,” he said.
Chronic pain patients would be best served by multidisciplinary pain management clinics that teach them the skills to manage their pain, as well as physical reconditioning, assessing their biomechanics, occupational therapy and procedures or medicinal treatments with evidence to back their effectiveness, Professor Vagg said.
The Medicinal Cannabis Industry Association said while the industry has only be able to legally conduct clinical trials in Australia since 2016, a body of evidence was emerging globally that supported the use of medicinal cannabis.
The industry group supported the formation of an independent advisory council to inform patients and ensure access to education and training for prescribers.
“[The association] believes that through a focus on balanced and evidence-based information, along with the industry adhering to high standards, there will be increased confidence in medicinal cannabis by patients, the medical/healthcare sector and community,” it said in a statement. Originally published here: https://www.smh.com.au/national/medicinal-cannabis-blacklisted-by-australian-pain-specialists-20210322-p57cyw.html