“Can a roadside drug test detect medications? I have ADHD and take a drug that is a type of amphetamine. Could I get busted for drug driving if I have taken my ADHD medication? What about other drugs that you may be prescribed by a doctor?”
Firstly, it’s important to remember that many medications, whether they’re prescribed by a doctor or bought ‘over-the-counter’ (OTC) from a supermarket or a pharmacy, can affect your ability to drive safely. Research has found that the use of some of these pharmaceutical products have led to a significant number of road deaths.
The initial test used in roadside drug testing (RDT) (or mobile drug testing (MDT) as it is called in NSW) is a simple saliva test. This is used to identify three illicit drugs – cannabis (or to be more specific, the active component of cannabis which is called THC), ecstasy (MDMA) and methamphetamine (speed or ice). NSW and Queensland now also test for a fourth drug – cocaine. It will not detect the presence of prescription drugs, including those medicines containing amphetamine-like substances, such as cold and flu tablets. According to police, you cannot test positive for amphetamine as you are only being tested for methamphetamine – amphetamine and methamphetamine are not the same drug. Taking ADHD medication such as dexamphetamine alone should also not produce a positive result on the initial roadside drug test. Once again, dexamphetamine and methamphetamine are not the same so it won’t be identified in this initial test.
That said, I have met young people who’ve told me that they failed the first test for methamphetamine and swear that they’ve never used that drug. It’s important to note that they all passed the second test – a far more accurate laboratory test that will certainly be able to distinguish between different forms of amphetamine – but that’s little comfort for those people who fail that first one through no fault of their own. If you are on ADHD medication and selected for an RDT and do return a positive test result for methamphetamine, don’t panic. You’ll still have to do the second test but if it is an ADHD medication that caused the problem, the more accurate test will make that clear.
Some antidepressants may also impair driving ability, particularly those that have a sedative effect and young people should be encouraged to speak to their doctor about the effect their prescribed medication may have on their driving, particularly if they’ve been using the drug for some time. Their doctors should be made aware that they’re now driving and, if the medication does have a potentially negative effect on driving skills, a different product may need to be prescribed. If you’ve only recently started to drive it may be a good idea to take your medication as you usually do and then ask a parent or a responsible friend to take a drive with you shortly afterwards and tell you whether they believe your driving is impaired in any way.
If you are stopped for a RDT or any other reason while you are driving and your behaviour or driving is erratic and police suspect you may be under the influence of any drug – legal, illegal or pharmaceutical, the police can require you to undergo blood and urine testing. The tests cover a large range of legal and illegal substances tand can lead to a charge of driving under the influence (DUI), which has serious penalties. If the drug is adversely affecting your driving ability, then regardless of whether it is prescribed or bought ‘over the counter’ then you can be charged with drug driving.
As already said, if you’re on any medication, talk to your doctor about what impact the drug may have on your driving ability. At the very least, read the instructions and warning labels. Even over-the-counter medications such as cold and flu preparations can impair driving ability, particularly if they’re not taken as directed. Antihistamines, which many young people use to treat allergies such as hayfever, can often cause drowsiness and even though you can buy ‘non drowsy’ preparations, it’s still extremely important that you read the packaging carefully before using and then driving. If you are in any doubt, ask the pharmacist about the drug’s potential effect on driving.
If there is any chance that the medication being taken could affect your driving ability, the message is clear – do not drive.
Please note that the advice provided is for information purposes only. As such, it cannot substitute for the advice of a legal professional.
First published: April 2019
Reviewed and updated: August 2023