Clinicians say they are cautious as demand for prescription cannabinoids outruns research on safety profile and effectiveness
Doctors have written to the Medical Journal of Australia (MJA) on behalf of the Royal Australasian College of Physicians (RACP), sharing their concerns that the introduction of medicinal cannabis has not followed the usual research-based safety and effectiveness processes.
While there is a growing community demand for prescription cannabinoids on compassionate grounds, the usual medical research standards have not yet been met, they say.
“While the RACP understands the community interest in cannabinoids as a therapeutic product, it emphasises that the usual regulatory processes designed to protect patients from serious harms are incomplete for medicinal cannabinoids, and that evidence for their effectiveness for many medical conditions is at present limited,” write Professor Jennifer Martin, Associate Professor Yvonne Bonomo and Clinical Associate Professor Adrian Reynolds.
“The Special Access Scheme (SAS) provides patient access to cannabis and other unregistered preparations on compassionate grounds without the usual quality and safety data requirements.”
The authors draw a comparison between medicinal cannabis and the introduction of opioid medicines.
“Treatment of persistent non-cancer pain with opioid medicines similarly began with little supportive evidence and has been associated with an epidemic of overdose deaths and poor pain outcomes, resulting in ongoing suffering.”
In an accompanying MJA narrative review, researchers from the Sydney Children’s Hospital and UNSW have reviewed use of cannabinoids for paediatric epilepsy.
They say anecdotal media reports of “miracle cures” have strongly influenced community perception, significantly affecting government policy and creating further complexity.
“High quality scientific evidence is essential to guide medical decision making and the political and legal framework,” says the research group led by Dr John Lawson, a paediatric neurologist and lead investigator in the NSW Ministry of Health-funded medicinal cannabis trials.
In regards to epilepsy, their narrative review found evidence for cannabis’ efficacy in treating the condition is limited but growing, with further clinical trials needed to clearly define efficacy and safety.
A 2017 randomised double-blind placebo-controlled trial of cannabidiol for drug-resistant epilepsy in children with Dravet syndrome found a median decrease of convulsive seizure frequency per month from 12.4 to 5.9 with cannabidiol, compared with from 14.9 to 14.1 with placebo.
However despite the positive results, the cannabidiol group experienced more frequent adverse events including vomiting, fever, illness, anorexia, seizures, sedation, diarrhoea and abnormal liver function test results, with 14.8% of the group withdrawing during the study period.
“There is a need for more scientific studies to understand the risk, benefits and reproducibility of cannabidiol in children with intractable epilepsy,” say the authors.
“The public perception and media hype must be tempered by clinical evidence.”
Confusion across the Pacific
Medicinal cannabis use in the US is also fraught with issues, and American physicians are similarly cautious about prescribing it as a treatment, despite cannabis having been legalised in several states.
A recent JAMA article shared survey results that revealed 30% of US clinicians had had patients or their families ask for medicinal cannabis at least once in the past month.
Seventy-nine percent of inquiries were to relieve nausea, 52% were for anorexia (appetite promotion), 26% were for pain, and 24% were for depression or anxiety.
Of all inquiries, only 14% of clinicians had actually facilitated access to medicinal cannabis.
Lead researcher Dr Joanne Wolfe, director of Paediatric Palliative Care at Boston Children’s Hospital, theorised that clinicians who are eligible to certify patients may have more understanding of the medicinal cannabis program in their state – including its nuances and clinical uncertainties – and therefore may be more cautious.
Despite legalisation in many states, cannabis remains classified as a schedule I controlled substance (considered to have a high potential for abuse and to be without medical value) by the Drug Enforcement Administration in the US, making it illegal under federal law.
Many American clinicians are unclear that it is actually against US federal laws to certify patients for medicinal cannabis treatment.
For nearly half the clinicians surveyed, the greatest barrier to recommending medical cannabis was lack of information surrounding formulation, potency and dosing.
Stefan Friedrichsdorf, medical director of the Department of Pain Medicine at Children’s Minnesota in Minneapolis, says he has chosen not to become a certifying physician due to the “unknowns”.
“I’m absolutely certain that there are very useful and good components in this compound, but we have to find out which ones and the safety profile,” he says.
“And with the current system, I have no control. I would certify it, and then my patients would go to a [dispensary] that has nothing to do with me, yet decides which brand to give, which strain to give, whether to go up or down in dosage.”