How does heroin affect driving?

Heroin is one of a group of drugs known as “opioids”. Other opioids include drugs such as morphine, codeine, pethidine, oxycodone, opium, methadone and buprenorphine.

This page covers the use of heroin, and some other opioids, whilst driving. If you are using an opioid prescribed by your doctor, read our fact sheet “Medication and driving” for more information.

Read the facts about heroin.

Effects of heroin and other opioids on driving

Heroin and other opioids are depressant drugs. This means they slow down the activity of the brain and other parts of the central nervous system.

The effects are influenced by a range of factors such as:

• the type of opioid, its strength, and if it is a prescribed medicine or illegally manufactured one. For example, heroin can vary in strength and purity so it can be difficult to predict the extent to which a person’s driving skills will be impaired after using heroin.
• how much is taken. Larger amounts can produce different effects. 
• how it is used. For example, injected, swallowed or smoked.
• the psychological and physical attributes of the person using it. Factors such as a person’s mental or emotional state and physical health can influence the effects of a drug.
  
  

This makes it difficult to predict exactly, in what way, and for how long, opioids will affect a person’s ability to drive safely. As a general guide, some of the effects may include:

• slow reaction time
• taking longer to respond to events or situations, and possibly choosing an inappropriate response
• reduced coordination
• reduced ability to think clearly
• changes to visual acuity, such as blurred vision
• drowsiness or starting to “nod off”
• nausea and vomiting. 

Some people may experience withdrawal symptoms when the effects of the heroin or opioid wears off. These can include cravings or “hanging out”, cramps and ‘flu-like symptoms which may also affect a person’s driving ability.

A person who has been using heroin may think that, if they are especially careful, they will be able to drive safely. However, the drug may have affected their view and experience of reality, and their judgement. Their actions and responses may be impaired, but they may not be aware of how much their driving skills have been affected.

Safer driving tips

If you intend to use heroin or opioids, the safest option is not to drive.

The effects of heroin and opioids may last up to 24 hours.

If you have used heroin or opioids make sure you have had several hours sleep and avoid driving late at night or early in the morning, when natural tiredness may increase the sedating effects of the drug.

Find more information for drivers.

Last updated: 27 April 2012