Behind the buzz: medicinal cannabis

Is medicinal cannabis a friend or foe? Demand for medicinal cannabis is booming, but experts are divided on its safety and efficacy. What conditions has it been proven to treat, how can you get it and are there risks?

By Sabrina Rogers-Anderson

Remember when cannabis was considered an illicit drug to be smoked secretly in a back alley?

All that changed in 2016 when the Australian Government passed legislation allowing doctors to prescribe unregistered medicinal cannabis products for a range of health conditions.

Since then, its use has skyrocketed. From a mere 18,000 in 2019, the number of Australians who use cannabis-based medicines now exceeds 1 million.

But what has it actually been proven to be effective for, is it safe and where can you get it? Here’s what the latest research and medical experts have to say.

What is medicinal cannabis?

Medicinal cannabis is a medicine derived from the cannabis plant. While this is the same plant recreational marijuana comes from, the street version is illegal in most states and territories (except the ACT).

“The two main compounds in cannabinoid-based medicines are THC [tetrahydrocannabinol] and CBD [cannabidiol],” Dr Cilla Zhou, Research Officer and Media Manager at the University of Sydney’s Lambert Initiative for Cannabinoid Therapeutics, told Citro.

“THC is the main compound that’s psychoactive, which means that it has an effect on the brain and makes you feel high. CBD doesn't make you feel high, but that doesn’t mean it’s not psychoactive. It still has an effect on the brain, but without the high.”

A variety of products containing CBD, THC or a combination of both are available in Australia in herb, capsule, inhaler, oil, oral spray and topical gel form.

What conditions can medicinal cannabis treat?

Medicinal cannabis is often prescribed to help manage: 

• Chronic pain 
• Cancer-related symptoms (such as pain, nausea and reduced appetite)
• Epilepsy
• Multiple sclerosis (MS)
• Anxiety
• Insomnia
  

But many of Australia’s leading medical experts are quick to point out that the scientific evidence to back up its effectiveness in treating some of these conditions, particularly chronic pain, simply isn’t there.

Australian Medical Association (AMA) president Steve Robson told the ABC that while medicinal cannabis has been shown to be useful in conditions including epilepsy and palliative care, the evidence was “very flimsy” when it came to chronic pain.

Royal Australian College of General Practitioners (RACGP) vice president Michael Clements echoed Robson’s position and added that he was concerned doctors might cash in on the high demand for cannabis products.

“There's quite a bit of evidence showing that THC can help with chemotherapy-induced nausea and vomiting, and any associated appetite issues cancer patients might have,” says Dr Zhou. “There’s also some emerging evidence that THC can promote sleep, but its effectiveness is highly variable and that's likely due to tolerance and regularity of use. When you’re using it to promote sleep, you're likely using it every night.

“The TGA down-scheduled low doses of CBD so that it's now legal to sell them over the counter, but there aren't currently any products available. There’s a bit of a lag with the commercial companies getting their products approved. But the issue is that there hasn't been much efficacy shown with CBD in lower doses. 

“In terms of high doses of CBD, we recently published a review that showed some efficacy in managing anxiety and substance use disorders.

“There are also a few clinical trials that are looking at the effectiveness of cannabinoids in treating inflammatory conditions including inflammatory bowel syndrome and arthritis, but more research is needed.”

For some medicinal cannabis users, the controversial drug has been a lifesaver. “After several years of taking antidepressants for depression and anxiety with limited effects, my GP suggested medical cannabis,” says David.

“I’ve been taking it for 3 years now and it’s changed my life. It’s made me happier and helped with sleep onset. I use it a few times a week and I feel I can stop quite easily without experiencing withdrawal symptoms.”

How do you obtain it?

The Therapeutic Goods Administration (TGA) is the government body that regulates all medications in Australia. When the TGA approves a medicine for a specific use, it’s then listed on the Australian Register of Therapeutic Goods (ARTG).

“Only two cannabis-based medicines are currently listed on the ARTG,” says Dr Zhou. “Sativex is a one-to-one THC-to-CBD product that's been approved to treat muscle spasticity in multiple sclerosis. Epidyolex is a CBD-only product approved to treat seizures associated with Lennox-Gastaut syndrome or Dravet syndrome, two severe forms of epilepsy.”

Even for those approved conditions, medicinal cannabis products aren’t subsidised by the government through the Pharmaceutical Benefits Scheme (PBS).

So, how are everyday Aussies getting their hands on “unapproved” cannabis products?

Any registered health practitioner (including GPs and nurse practitioners) can apply to the TGA for approval to prescribe medicinal cannabis to a patient under the Special Access Scheme (SAS). They must justify their request and explain why other medications listed on the ARTG aren’t suitable for their patient.

An easier and more common way to obtain a script is through the Authorised Prescriber (AP) pathway. Any Australian registered medical practitioner can apply to become an AP. Once approved, they have the power to prescribe cannabis products to their patients without applying to the TGA.

“Online medicinal cannabis clinics are an increasingly popular method of accessing it,” says Dr Zhou. “A positive aspect of these clinics is that the clinicians are specialised in prescribing medicinal cannabis, so they have training and knowledge that your regular GP might not have.

“But on the other hand, telehealth clinics probably don’t have access to your broader medical history. I recommend people go to their regular health professional who knows their history even if it’s a slightly more complicated process.”

The RACGP’s Dr Clements is concerned that medicinal cannabis telehealth doctors are incentivised to quickly sign off on prescriptions. 

"We shouldn't be able to profit or make money from the treatment we're recommending," he told the ABC.

“These companies solely exist for the purposes of mailing out the cannabis product, so you don't have to try very hard to convince a doctor that that's the product for you. As long as you press the right buttons in the right [order] you're going to end up with a script for a product that you ask for, and that just doesn't sit with us well as GPs."

What are the risks?

Because medicinal cannabis isn’t approved for the vast majority of conditions it’s prescribed for, the TGA has no control over its quality and safety. 

“I can only talk about risk from a research perspective, so I encourage people to speak to their health professional to find out their personal health risk,” says Dr Zhou.

“The main risks are around the use of THC. A lot of people use it daily and in potent doses to manage their symptoms, and this can lead to a higher risk of experiencing cannabis use disorder. With THC, there’s also a risk for people who have a history or family history of psychosis-related disorder.

“Cannabinoids are known to interact with enzymes that metabolise the drugs in our bodies, so it's important to verify any possible interactions with other medications.”

When Danielle tried medicinal cannabis for her anxiety, she wasn’t worried at all because she’d smoked recreational marijuana in the past. “I only had a tiny bit and next minute, I thought I was on an acid trip,” she says. “I walked out of the shower and lay down on my bed soaking wet, thinking, ‘This is not okay.’ It made my anxiety so much worse, so I just threw it out and never touched it again.”

Some experts, including Monash University pain researcher Professor Rachelle Buchbinder, worry that a cannabis epidemic could replace the opioid one. And with her review of the data showing that it has very little effect on pain, she feels it would be all for nothing.

But academic director of the Lambert Initiative for Cannabinoid Therapeutics Professor Iain McGregor told The Sydney Morning Herald that these concerns were overblown.

“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.”

Making an informed decision

Is medicinal cannabis right for you? The best way to find out is to ask your GP who will take your entire medical history and list of medications into account.

Obtaining an instant script through an online cannabis clinic may seem easy, but you’ll have peace of mind knowing that you have medical clearance to give cannabis a go.

_{The information on this page is general information and should not be used to diagnose or treat a health problem or disease. Do not use the information found on this page as a substitute for professional health care advice. Any information you find on this page or on external sites which are linked to on this page should be verified with your professional healthcare provider.}