Can you use medicinal cannabis and drive?
If you’re thinking of using medicinal cannabis for a health condition, it’s an important question to ask.
Because let’s face it, cannabis has long been known as a plant that gets you “high” and no one wants to drive while inhibited.
But, of course, you’d like to maintain your freedom to drive to work, drop off and pick up the kids, get away for the weekend — all of which require the ability to drive.
There are many different common medicines that come with warnings about driving.
So what’s the deal with driving on medicinal cannabis?
It all depends on the type of medicinal cannabis you’re using.
Let’s cover the general rules around medical cannabis, CBD, THC and driving.
Using medical cannabis and driving in New Zealand
First off, this is general guidance. You should always talk to your doctor about how a medicinal cannabis product may affect your driving.
It’s important to know that not all medicinal cannabis is the same.
Each medicine contains different amounts of the plant’s active compounds, which produce different effects on the mind and body.
The most important of these compounds are cannabinoids.
Cannabis contains around 100 unique cannabinoids, the most well-known being CBD and THC.
CBD and THC are the two most important ingredients to consider when it comes to using medicinal cannabis and driving.
CBD and driving: Is it safe?
CBD is one of the main compounds used in medicinal cannabis, which has been found to interact with the body’s Endocannabinoid System.
CBD is not intoxicating and does not produce the “high” that cannabis is known for.
Therefore, you should be safe to use CBD-based products and drive.
A report by the World Health Organisation on CBD said there are no public health issues, such as driving under the influence of drugs cases, associated with the use of CBD.
A 2020 study in the Netherlands found that using CBD-dominant cannabis did not impair thinking or driving skills compared with placebo.
So what is a CBD-based or CBD-dominant product?
It’s a medicinal cannabis product that contains high amounts of CBD and only trace amounts of THC.
In some cases, you can get pure CBD that does not contain other cannabinoids.
Full-spectrum CBD is a CBD product that contains all of the available compounds in the cannabis plant, including terpenes and fatty acids, but only tiny amounts of THC (less than 0.3%).
While full-spectrum CBD does not contain enough THC to get you high or impair your driving, it may still show up in a roadside drug test.
The government has said the threshold for “impairment levels” in roadside drug tests will be aligned with alcohol levels. It’s highly unlikely CBD-dominant products will meet that threshold.
However, it’s a good idea to keep a copy of your prescription in your vehicle for the unlikely event that you’ll need to explain why THC is present in your system.
The government has said there will be a medical defence for anyone found driving with drugs in accordance with a prescription.
Verdict: Evidence suggests you’ll be safe to drive, but may test positive for THC.
Broad-spectrum CBD contains all of the available compounds in the cannabis plant but has no THC at all.
It will not produce any intoxicating effects, impair your driving, or be detected in a roadside drug test.
Verdict: Evidence suggests you’ll be safe to drive.
CBD isolate is pure CBD, containing no other cannabinoids or compounds from the cannabis plant.
Verdict: Evidence suggests you’ll be safe to drive.
THC and driving: Is it safe?
THC is another of the main compounds in the cannabis plant and is present in many medicinal cannabis products.
It is the main compound that produces the high feeling cannabis is known for, but scientists have found it also has many therapeutic applications.
Medicinal cannabis products containing THC can have side effects that include dizziness, disorientation, coordination problems and slower reaction times.
Therefore, you shouldn’t drive after using medicinal cannabis that has THC. It will show up in a roadside drug test and may exceed the threshold of impairment, which can lead to infringement notices, fines, and even prison for recidivist offenders.
A 2019 study in Australia found that both THC-dominant strains and strains containing equal amounts of CBD and THC impaired driving.
It’s impossible to say how much THC it takes to produce intoxicating effects, which is why it’s important to ask your doctor about the specific cannabis-based medicine you’re being prescribed.
Learn more about CBD:THC ratios here.
The effects of THC can last for hours. The Netherlands study referenced above found drivers were impaired four hours after vapourising high-THC cannabis.
So if you were to take a THC-based medicine in the evening, it may be possible that you can drive unimpaired in the morning.
However, if you have a health condition that requires you to use THC throughout the day, you shouldn’t be driving.
Again, you’d have to consult your doctor to be sure about your specific situation.
The one time when you should be safe to use THC and drive is when you’re using a full-spectrum CBD product as described above, which contains less than 0.3% THC.
The highway to health
As you can tell, the question of using medicinal cannabis and driving is a complex one.
The general rule is that CBD-dominant medicines are safe and THC-dominant medicines aren’t.
However, CBD won’t always be the most appropriate medicine for your specific health condition or symptoms.
Patients who are prescribed THC-dominant medicinal cannabis may find restrictions around driving and other everyday tasks.
As with other medications that make you feel drowsy or affect concentration, your doctor will be able to provide you with personalised advice.
But make sure to do your own research, read the label of any medicinal cannabis products you’re using, and err on the side of caution when it comes to driving.