Medicines and driving

Some prescription and over-the-counter (OTC) medicines can affect you in a way that makes it unsafe for you to drive. In New Zealand, it is against the law to drive while impaired.

If you are taking medicines and are driving, it is important to do the following:

  • Know how your medicines can affect you by asking your doctor or pharmacist.
  • Check how you feel before and while you drive.
  • Stop driving or don’t start driving if you feel impaired.

How can medicines affect driving?

Some medicines can affect your concentration and how you focus or pay attention. They can slow your reaction times and cause sleepiness or drowsiness, blurred vision, dizziness, slowed down movements and fainting, or make you feel anxious or jittery. Do not drive if you have any of these.

Not taking medicines can also be a risk

Not taking some medicines while driving can also be risky.

  • Epilepsy – some people with epilepsy may not be able to drive at all without taking their regular medicines. Read more about driving with epilepsy.
  • Diabetes – for drivers with diabetes, it is important to take your regular medicines as prescribed because high blood glucose levels can make you feel unwell and tired and may affect your ability to drive. Your blood glucose levels may get too high if you miss doses. You should not drive if your blood glucose is too high (hyperglycaemia).

Which medicines are most likely to affect driving?

Always ask your doctor or pharmacist if your medicines are likely to affect your driving. Some types of medicines known to affect driving include: 

Note: Combinations of medicines and medical problems may affect people differently.

How long should I avoid driving for?

It is important not to drive until you know how your medicine affects you. Some medicines only have short-term effects when you first start taking them or when you change the dose. This means you might only need to stop driving for a few days until your body adjusts.

However, for other medicines you will need to stop driving while you are taking them. Learn to know how your body reacts to the medicines and supplements you are taking. Keep track of how you feel and when the effects occur.

Alcohol, medicines and driving

Drinking alcohol and taking medicines that affect driving increases your risk of having a car crash. It can make you 23 times more likely to have a fatal crash (that causes death) than drivers who have taken none of these.

Alcohol can add to the effects of medicines on your coordination, reaction time, sleepiness and more. Even though you might be under the legal alcohol limit, you might still be affected and unable to drive.

Older adults, medicines and driving

Medicines that usually cause drowsiness and changes in concentration effect older people more because of age-related changes in the way your body breaks down medicines. This is of concern because older people often take several medicines to stay well, including some that may affect driving. Combinations of medicines can cause more side effects. 

Tips for taking medicines and driving

  • Ask your doctor or pharmacist if the medicines you are given affect driving and whether it is safe for you to drive.
  • Read your medicine labels to see if it can affect your driving.
  • If you feel that the medicine you are taking is affecting your driving, talk to your doctor. They may be able to adjust the dose or the timing of doses, or change the medicine to one that causes less drowsiness.
  • Consider other options instead of driving, such as rides with family and friends, taxi, buses, trains or walking.  

Learn more

Are you safe to drive? NZ Transport Agency
Older drivers National Institute on Aging, US 

References

  1. Driving rules and assessment for older people BPAC, NZ, 2010
  2. Drugs and driving New Zealand Formulary
  3. Medicines can impair driving Medsafe Prescriber Update, NZ 2016
  4. Medical aspects of fitness to drive NZ Transport Agency, 2014
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 16 Jun 2020