Drug Driving

Driving under the influence of drugs can have serious consequences for you and others.

It’s illegal to drive if you are impaired by drugs or have certain drugs over a specified limit in your blood. Along with breathalysers, police now have roadside  tests for some illegal drugs. They can detain you for further blood or urine testing at a police station if they suspect you have drugs in your system. If the tests prove positive then you will be charged with drug driving.

This applies not just to illegal drugs, but also to prescription or over-the-counter medication. Some medications can have a serious effect on your ability to drive so always check with your doctor or pharmacist, and do not take drugs which have not been prescribed for you.

Many drugs take time to leave your system, and will still have an impact on your ability to perform complex tasks like driving long after you have taken them. Any substance that affects your concentration, perception, reaction time, manual skills, decision making and mood will make you unsafe behind the wheel. Don’t put yourself, your passengers or other road users at risk.

The penalties for drug driving are the same as for drink driving. If you are convicted you will receive:

  • A minimum 12 month driving ban
  • A criminal record
  • An unlimited fine
  • Up to 6 months in prison
  • An endorsement on your license for 11 years

Beyond the legal consequences, a drug drive conviction can have far reaching effects on your life.

  • Job loss
  • Difficulty finding new employment
  • Increase in car insurance, and difficulty obtaining any kind of insurance
  • Difficulty getting a visa or work permit to travel abroad, such as the USA
  • Impact on college or university education


Legislation introduced in 2015 sets out permitted levels in micrograms per litre of blood for both medicinal and illegal drugs. A microgram is a millionth of a gram, so this equates to an almost zero tolerance approach in some cases.

'Illegal' drugs

  • Benzoylecgonine (metabolised cocaine) 50µg/litre of blood
  • Cocaine 10µg/litre
  • Delta-9-tetrahydrocannibinol (cannabis) 2µg/litre
  • Ketamine 20µg/litre
  • Lysergic acid diethylamide (LSD) 1µg/litre
  • Methylamphetamine (Crystal Meth/Speed) 10µg/litre
  • MDMA (ecstasy) 10µg/litre
  • 6-monoacetylmorphine (heroin) 5µg/litre

'Medicinal' drugs

  • Clonazepam 50µg/litre of blood
  • Diazepam 550µg/litre
  • Flunitrazepam 300µg/litre
  • Lorazepam 100µg/litre
  • Methadone 500µg/litre
  • Morphine 80µg/litre
  • Oxazepam 300µg/litre
  • Temazepam 1,000µg/litre
  • Amphetamine 250µg/litre​

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