How can medicines affect driving?
Some medicines have side effects that can affect your ability to drive safely. Like drink driving, it is illegal to drive under the influence of drugs, whether they are legal or illegal.
To drive safely, you need to be able to see, think and react properly. Some medicines, both prescription and over-the-counter medicines, can affect these skills. If you are taking these medicines, it may not be safe to drive.
The risks are greater if you are taking more than one medicine, or if you drink alcohol while you are taking medicines.
Some common side effects of medicines that can affect your driving include:
- feeling drowsy or tired
- feeling dizzy, faint or nauseous
- blurred or double vision
- shakiness or unsteadiness
- confusion and being less alert
- not being able to concentrate properly
- not being able to judge distance or speed properly
- reacting more slowly
- muscle weakness or being less coordinated
- anxiety or other changes to your mood
Some medicines can affect your driving so significantly that they are equivalent to drinking more than the legal limit for alcohol.
If you think your medicine is affecting your driving, do not stop taking it. Stop driving and talk to your doctor. There might be other medications you can take.
Which medicines could affect my driving?
Some examples of medicines that might impair your driving include:
- sleeping pills and medicines for anxiety
- epilepsy medicine
- some antidepressants (used for nerve pain, migraines, bladder problems and depression)
- antipsychotics (used for conditions like schizophrenia and bipolar disorder)
- some antihistamines (used for allergies, colds and flu)
- opioids (used for pain relief)
- some cold and flu preparations
- some medicines for blood pressure, nausea, inflammation or fungal infections
- diet pills
- medicinal cannabis that contains delta-9-tetrahydrocannabinol (THC). Cannabidiol does not contain THC but it can also cause drowsiness, fatigue and low blood pressure, so talk to your doctor about whether it is safe to drive
Not everyone's driving will be affected by these medicines. It depends on your tolerance of the medicine, how long you take it before you drive, what other medicines you are taking, and your medical condition.
Some medicines can make you a safer driver by treating conditions that would affect your driving, such as diabetes, epilepsy or heart disease.
What to do
- Ask your doctor or pharmacist whether it is safe to drive.
- Always read and follow the instructions on the medicine's warning label.
- Remember that the medicine might affect your driving more when you first start taking it. Over time, you may get used to it and experience fewer side effects.
- Do not stop taking your medicine or alter the dose without talking to your doctor first.
- Talk to your doctor about switching any medicine that affects your driving.
- Do not take more than the prescribed dose of the medicine.
- Do not drink alcohol or take other drugs while you are taking medicines.
- Do not drive if you have missed a dose of medicine that you need to control symptoms that could affect your driving.
- Arrange another form of transport, such as public transport or a taxi.
Prescription medicines and driving laws
Driving under the influence of drugs can carry heavy penalties. If you have a medical condition that could affect your driving, you will need to inform your state or territory licensing authority. You may need to provide a medical report from a doctor stating that you are fit to drive.
State and territory governments are in charge of road rules and road safety. You can find specific information in your state or territory at:
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Last reviewed: May 2021