The way our bodies process foods, drinks, and medication can change with age. All medications can cause side effects, and these side effects can increase with the more medications you take. Side effects from medications can start appearing, even if you have never experienced side effects before.   

Any medication with side effects can cause problems with concentration, alertness, vision, and reaction time, this can have serious consequences when performing complex tasks.   

1 in 3 Australians take more than one prescribed medication in a week.1  

Operating machinery and/or driving, particularly operating a heavy vehicle is a complex task that requires you to be alert and respond quickly. Anything that is disruptive to performing the driving task, securing your load, or even getting in and out of the vehicle, can have serious consequences to yourself and others sharing the road.  

Common side effects from medications to look out for:   

  • Sleepy or tired  
  • Changes in vision (e.g., blurred, double vision)  
  • Dizziness, light-headed or faint feeling  
  • Muscle weakness  
  • Feel unsteady or anxious  
  • Changes in mood (e.g., feeling angry)  
  • Slow reaction time  
  • Difficulty concentrating or confused  

The way your medications interact with each other can affect your performance. Ask your pharmacist about the side effects of your medication.   

Medications include:   

  • prescriptions by a GP or doctor;   
  • over the counter from pharmacies, supermarkets and health food stores (this includes ointments, tablets, syrups, inhalers and suppositories);   
  • herbal and homeopathic products including vitamin and mineral supplements.  

What you eat and drink can affect your medications. For example, grapefruit and grapefruit juice, vitamin K rich foods, potassium and alcohol can increase the risks of side effects of medications.   

Medications used to treat the following conditions can impact your driving skills:  

  • Sleep problems  
  • Heart conditions  
  • High blood pressure  
  • Inflammation  
  • Heartburn and indigestion  
  • Migraines and headache  
  • Cold and allergy  
  • Pain relief  
  • Anxiety and depression  
  • Mental illness  

Ask your pharmacist or your GP about your medications, or visit our Support page for helpful links. 

Find more detailed information on the effect that medications can have on your driving here.   


  1. NPS MedicineWise. With millions taking multiple medicines, Australians are reminded to Be MedicineWise. NPS MedicineWise (2018)