In 2012, the UK government brought in tough new legislation to deal with the growing number of drug-driving related incidents. For many people, drug driving is synonymous with the taking of cannabis, cocaine, heroin or other mind-altering substances, usually for recreational use.

What most drivers don’t realise is that the drug-driving laws can apply to any drugs – including prescribed and over-the-counter medications. So, before you happily pop your next round of pills before heading out to work, it’s worth checking that you are road-legal first.

What is drug-driving?

The way the police ascertain if you are guilty of drug-driving is if:

  • Your ability to drive is impaired, either by legal or illegal drugs.
  • Your blood contains more than the legal limit for certain illegal drugs, regardless of whether your driving is impaired.

For some drugs, taking them in any amount will undoubtedly affect your ability to drive, hence the second bullet point above. For others, such as prescribed medications, your ability to drive is not always affected, hence the first bullet point – though if your driving is impaired, then taking prescription medicine is no defence.

Zero tolerance

According to the DVLA, eight drugs – including cannabis, MDMA, heroin and cocaine – fall into the second bullet point category, and have extremely low limits set on them, which realistically means that any usage will render you above the legal limit.

Something that few people realise, too, is that many drugs remain in your body’s system for extended periods of time – for example, you could still be over the limit for cocaine up to 48 hours after taking it.

For the full list of named drugs and their thresholds, along with more details on the 2015 changes to drug-driving laws, take a look at the UK government’ reference page ‘Drug Driving Limits’.


The police aren’t interested in making your daily commute more difficult than it needs to be – they simply want to be sure that anyone driving a vehicle is safe to do so. With this in mind, eight notable prescription drugs have been specified in the new 2015 laws as being legally allowed whilst driving, to enable people taking them to go about their daily lives:

  • diazepam
  • clonazepam
  • flunitrazepam
  • lorazepam
  • oxazepam
  • temazepam
  • methadone
  • morphine

For these drugs, police officers will take into account whether your ability to drive is impaired, often by simple roadside tests such as walking in a straight line. If you are fit to drive, then having them in your system at the prescribed levels is not a problem.

Over-the-counter (OTC) medications, taken at the correct dosage, are generally not potent enough to cause issues – so taking things like paracetamol for a headache is fine. However, some hay fever sufferers have been caught out by products containing certain ingredients that can cause drowsiness whilst driving. If you drive vehicles regularly then make sure you are fit to drive. Do please be aware, too, that taking more than the recommended dose of any OTC medication can exacerbate side effects.

Furthermore, some people have more extreme reactions to medications than others, and so if you feel your driving is impaired in any way by the drugs you are taking, it is safer not to drive. If you are involved in an accident, or pulled over by the police and found to be impaired, then you will be charged with drug-driving, irrespective of the fact that you’ve been taking legally prescribed drugs.

Most drug packaging comes with information on whether you are safe to drive whilst taking the product, and doctors will give their own advice based on your dosage and individual circumstances. If a medical professional tells you not to drive whilst taking certain medicines, you should follow their advice for the duration of your treatment.

If you are taking medication, it is worth keeping your current prescription slip in the car in case you need to provide evidence of this to police, as this will save a lot of time and hassle at the roadside.

What if I’m charged with drug-driving?

If you are found guilty of drug-driving offences, the penalties can be severe depending on your situation, the drugs in question, and the level of drugs in your system.

You will get a minimum 1 year ban on driving and an unlimited fine, as well as up to 6 months in prison and a criminal record. The penalty for causing death by dangerous driving whilst under the influence of drugs is up to 14 years’ imprisonment.

The conviction will show on your driving licence for 11 years, and may prevent you from travelling to certain other countries, such as the USA. It will undoubtedly also cause a significant increase in your car insurance premium.

Drug-driving around the UK

It is worth noting that the above legislation is currently valid for all parts of the United Kingdom; however, Scotland is looking to introduce tougher laws on drug-driving. Currently, Scotland has a zero-tolerance stance on drink-driving – unlike in the rest of the UK, where 35mg of alcohol per 100ml of blood is permissible.

The Scottish government is keen to push through similarly stringent measures for drug-drivers, which would remove the question of impaired driving, and charge drivers purely on whether they are over the allowed limits for prescription drugs. Being over the limit for prescribed medication is possible if the drug has accumulated in your system over many days, even if you’ve been taking the correct dose. You can read more about the government’s decision to pursue this course of action here.

Know the facts

The Department for Transport has created a handy video to give you the basic facts about the new laws. Illegal drug use is fairly straightforward, but for those of us on prescriptions, there’s really only one thing to remember: The responsibility is on you to ensure any legal drugs don’t impair your ability to drive. If they do, it’s simple: don’t get behind the wheel.

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