In a conference room in Melbourne last week, a course was underway teaching doctors about medicinal cannabis and how to prescribe it.

Described as an Australia first, the course aimed to fill a “vacuum” in the knowledge base of the medical profession, says its architect emergency doctor and Australian National University academic Dr David Caldicott, who hopes it will become an accredited RACGP CPD program.

The one-day course – which opened the 2017 United in Compassion Medical Cannabis Symposium at Crowne Plaza – covered everything from the history and politics to the nitty gritty of suitable indications and dosing regimens – largely based on research and experience overseas.

The United in Compassion Symposium, photo credit to UIC.

Attracting over 90 participants, including GPs, palliative care physicians and nurses, it received an “embarrassingly positive” response, including requests to run the course in other states, Dr Caldicott tells the limbic.

The course is open to all, but targeted to GPs, neurologists, pain specialists, paediatricians and palliative care specialists.

Dr Caldicott says he is targeting those doctors who treat patients for the range of conditions for which medicinal cannabis is indicated: pain, chemotherapy-induced nausea and vomiting, intractable paediatric seizures, and end-of-life pain and associated anxiety.

But the quality of evidence to support using medicinal cannabis to treat many of these listed conditions is called into question by the Royal Australasian College of Physicians.

There are two pathways for doctors to prescribe unregistered medicinal cannabis products outside clinical trials, and the numbers doing it are low.

Doctors can use the TGA’s special access scheme or become an authorised prescriber for a specified medical condition.

In some jurisdictions, further sign offs are needed by a state health department.

A Senate Estimates hearing in May heard Australia has just 25 authorised prescribers – 24 are paediatric neurologists and one is a palliative care physician – while  66 special access applications were approved this year.

While figures from the hearing indicate less than 150 patients have been prescribed medicinal cannabis through these channels, tens of thousands more are sourcing cannabis for therapeutic purposes through illicit means says Dr Caldicott, the figure is based on reports from community-based patient support groups.

He claims Australia is too conservative in its approach to the subject.

“There are a couple of lines of opposition (to medicinal cannabis) and one of those is that we don’t know enough about it to prescribe it. That’s patently not true because many others have been doing it, and for quite a while – just not in Australia.”

Medicinal cannabis dosing guidelines have been developed in Israel and Holland, he says.

“There is a narrative in Australia that medicinal cannabis is the same as recreational cannabis, is dangerous, and no-one should use it in its botanical form, and then there is the global narrative – which is that cannabis is interesting, has huge potential, that there may be many indications, and it’s certainly benefiting some people- right now,” he says.

In a rapidly changing landscape, where a loud patient advocacy voice is calling for access on compassionate grounds and state and federal legislation is being regularly amended, he argues that the medical community needs to be up to speed on the issue.

“The point of the course is GPs, among others, will have the knowledge to scientifically decide not to prescribe cannabis, as much as to prescribe it.”

It’s fair to say the medical profession at large in Australia is cautious about the claimed benefits of medicinal cannabis.

The Royal College of General Practitioners’ position statement from October 2016 says the evidence is “incomplete”, describing only “moderate quality evidence” to support cautious use of cannabinoids for treating symptoms for a narrow range of conditions – namely arthritis, chronic non-cancer pain and multiple sclerosis-related spasticity.

The statement also highlights increased risk of short-term adverse events, with findings of a pooled analysis suggesting a three-fold increase compared to placebo or alternative medication.

It concludes that the medical profession and the wider public do need education, and that this education should “contextualise the use of medical cannabis as a last-resort medication for specific categories of illness that can only be prescribed in rare circumstances after stringent legislative criteria are satisfied”.

Dr Caldicott believes this statement may be out of date, arguing it was published before the release in January of a comprehensive literature review by the National Academy of Sciences Engineering and Medicine (NASEM).

This review finds cannabis or cannabinoids have therapeutic benefits including reducing chronic pain, multiple sclerosis-related muscle spasms, and chemotherapy-induced nausea and vomiting in adults.

“The (report) also concurs with the utility of medicinal cannabis for the treatment of pain, considering the evidence as being ‘substantial’. Regarding the treatment of nausea, they regard the evidence as being ‘conclusive’,” he says.

“In contrast, in Australia, the indications are restrictively small, for example in Victoria it’s only paediatric epilepsy. There is a very narrow, conservative approach to this field in Australia.”

The NASEM report finds cannabis use leads to an increased risk of developing schizophrenia, other psychoses, and social anxiety disorders.

But Dr Caldicott claims there is “no significant data that shows cannabis directly causes psychosis”.

“There is merely an association; there is a huge difference between causality and association… [but] it is still something we need to pay attention to, which is why in many jurisdictions, a history of psychiatric illness constitutes a contraindication for use”.

The Royal College of Physicians has much more measured view on the benefits of medicinal cannabis and case for prescribing it in Australia.

Dr Adrian Reynolds is a clinical associate professor and the RACP’s Australasian president of the chapter of addiction medicine.

He questions the utility of courses training doctors to prescribe a medicine “that is not yet registered and for which we don’t have good even adequate knowledge, data, science for demonstrating efficacy, quality, safety”, but stresses that the RACP has not adopted a position on whether such courses should be offered.

“I would be interested to see what David’s reference for medical conditions for which doctors ought to be prescribing at this time in history, because it is a vexed question for the medical profession right now,” he says.

Dr Reynolds says he’s well aware of the NASEM review, and its findings report positive, not so positive and serious adverse outcomes associated with cannabinoids.

It also reports clinical outcomes associated with therapeutic claims ranging from little or no evidence of benefit or harm, to substantial evidence of either or both outcomes, he says.

Overall, he says the case for medicinal cannabis is far from proven, and one colleague has counted over 140 medical conditions for which there are claims of therapeutic benefits for cannabinoids.

“If we go to the experts in palliative care and pain medicine, they have said there is not good quality evidence to guide practice in this area and it’s not clear in any case (whether) what benefits might be achieved outweigh the potential side effects.

“The effects, where they may be measured, are not significant and not better than currently available treatments, for which there is a strong evidence base that’s been presented through the regulators for approval as a registered medicine by the TGA.”

He points to the Faculty of Pain Medicine’s 2015 statement on the subject, which says there is little evidence for the effectiveness of cannabinoids for non-cancer pain – with the possible exception of pain and spasticity in multiple sclerosis – and it won’t endorse its use until there is.

“If the Israelis really have been using these medicines for 20 years to good effect why haven’t they published the data that would demonstrate the effectiveness to a standard we would all accept in medicine?” Dr Reynolds argues.

“Medicine cannot, on the basis of well-meaning lay comments in the community asserting benefits, simply start prescribing in the absence of fair guidance around that evidence base.”

“I am not at all comfortable with the advocacy and pressures being applied to the medical profession by those who are too ready to abandon standard scientific processes. Neither is the College.”