Experts call for reforms to medicinal cannabis roadside testing

Published: 3 February 2025

Picture this: You are legally prescribed medication for pain management by your doctor and take the prescription responsibly. Despite not being impaired, you now cannot legally drive or else risk a fine and loss of your driver’s licence.

This is the reality for many people who are prescribed medicinal cannabis. Southern Cross University Dean of Law, Professor David Heilpern, is calling for reforms to road laws surrounding medicinal cannabis to ensure patients aren’t unfairly penalised for seeking treatment.

“The vast majority of people who receive a script for medicinal cannabis have tetrahydrocannabinol (THC) in their prescription, which is detectable in roadside random drug tests,” Professor Heilpern explains.

“If THC is detected in your saliva, then it’s a criminal offence. You can be fined and you can lose your licence.

“In Australia, we’ve just passed a million scripts for medicinal cannabis, many of which would include THC. And so, every single one of those people who fill and use that prescription are committing criminal offences if they drive on any road throughout Australia.”

In New South Wales, more than 225,000 random drug detection tests are conducted every year. Australia has one of the largest roadside drug testing programs in the world, according to the National Road Safety Strategy.

“That is a huge resource put into policing. This is the only prescription drug where detection is an offence,” Professor Heilpern says.

Dean of Law, Associate Professor David Heilpern

Some over-the-counter and prescription medications including cold remedies such as Phenergan, sleeping tablets, pain and opioid medicines such as Endone, and antidepressants can cause driver impairment, according to NSW Health. However, roadside drug tests do not pick this up.

“The current detection methods do not test for impairment. No one is talking about decriminalising driving under the influence when you’re adversely affected. That should always remain an offence whether it’s a prescription drug or illicit drug,” he says.

“But these laws were put in place at a time where cannabis was completely illegal. Now that prescribed medicinal cannabis has been legalised, the driving laws need to catch up.”

For people in regional and rural areas where public transport options and access to healthcare are limited, the impacts of the current laws are far-reaching.

“When I was a magistrate, I was required to take people’s licence from them if they tested positive to THC while driving,” says Professor Heilpern. “And that’s one of the reasons I left the job.

“Even though they had a prescription and even though there was no hint that they were driving adversely. For most people in regional and rural areas, there is no public transport and if you lose your licence, you could lose your job.

“There’s an enormous social isolation in rural and regional areas that is exacerbated by the tyranny of distance. All of the reasons a person might be using cannabis are only exaggerated by an increase in social isolation.”

Applying a health lens to a legal issue

Medicinal cannabis can be prescribed to help mitigate a number of health issues from pain management to cancer symptoms and epilepsy.

Southern Cross University’s National Centre for Naturopathic Medicine (NCNM) has been undertaking national research into the plant, its properties and health benefits.

NCNM Foundation Director, Professor Jon Wardle, explains: “Cannabis is a treasure trove of chemicals and we are seeing a lot of interesting uses come up, from a replacement for Botox for people with bladder issues to potential improvements in insomnia all the way to topical use for certain cancers and tumour growth”.

Southern Cross is host to the largest genomic data bank of medicinal cannabis products outside Germany, with research underway investigating the cultivation, production and development of cannabis products.

“We have incredible researchers. People like Dr Janet Schloss, who is doing a lot of research into pain and fibromyalgia. Dr Andrea Bugarcic is doing a lot of interesting work pre-clinically to find out what kind of impacts cannabis has on different cells,” Professor Wardle says.

“I like to think of Southern Cross as a hive of cannabis activity. We really look at everything from plant to patient.”

Professor Jon Wardle standing in front of greenery

Professor Wardle is a public health researcher and is convenor of the Public Health Association of Australia’s special interest group in complementary medicine.

“I think that education is really important because one thing we do worry about from a public health perspective is that there is an almost faddishness around cannabis. There is a bit of a health halo that all cannabis is good and all cannabis is good for everything. Cannabis is fantastic for some things but also potentially risky if abused,” he says.

Bringing drug laws up to speed

Professor Heilpern says there are other countries where drug use is treated as a public health issue and that Australia could draw valuable lessons from their strategies.

“In Portugal, cannabis has been decriminalised as has a suite of other drugs. In combination with a significant emphasis on rehabilitation, this has led to a decrease in the abuse of drugs as well as drug overdose,” he says.

“If Australia were to follow suit, the side effects would be enormous in terms of police time. A more productive legal environment will lead to a more productive medical environment, where people can seek treatment without stigma.”

Listen to Professor David Heilpern and Professor Jon Wardle discuss drug law reform on the SCU Buzz podcast.