It's important to understand the law around taking prescription drugs and driving.
The law is to catch people who risk lives. It's not to catch people who legally take medicines which do not affect their driving.
You'll only commit a crime if:
- you were not prescribed the drug
- it affects your driving
- you do not take prescription drugs as advised
It's a crime to drive if you're:
- over the limits for certain prescription or illegal drugs
- unfit because you've taken any drug
You can be convicted of either crime.
1. Driving over drug limits
The limits for prescription drugs are set at levels which clearly affect driving.
The prescription drugs the law applies to are:
- amphetamine including dexamphetamine (ADHD)
- clonazepam (epilepsy and other seizure disorders)
- diazepam (anxiety, alcohol withdrawal and muscle spasm)
- flunitrazepam (insomnia)
- lorazepam (anxiety and insomnia)
- methadone (drug addiction withdrawal and pain relief)
- morphine (pain relief)
- oxazepam (anxiety and insomnia)
- temazepam (insomnia and sedation before medical or dental procedures)
What the limits mean for you
The limits are what's measured in your blood and not how much you can take.
Many factors affect this including:
- how hydrated you are
- how your body tolerates the drug
It's impossible to say for sure what dose of any drug will put you over the limits or how safe it is to drive after taking it.
But you do not need to worry about being over the limits if:
- you were prescribed the drug
- you take it how your healthcare professional advised
- it does not affect your driving
2. Unfit to drive through drugs
It's a crime to drive after taking any drug that affects your driving.
For example if it makes you drowsy or affects your judgement or concentration.
This applies to any drug and includes:
- prescription drugs (for example tramadol, diazepam or medicinal cannabis)
- over the counter medicines (for example co-codamol or antihistamines)
- illegal drugs (for example cocaine or cannabis)
It's up to you to be sure you're fit to drive.
Roadside drugs test
The police can stop you if they think you're drug driving.
make you do a field impairment test – including checking your pupils and asking you to walk in a straight line
test you at the roadside for illegal drugs using saliva from a mouth swab
The police will arrest you if you fail either of these tests.
They will then take you to a police station for blood tests.
At this point you could be charged with a crime.
What happens if you're convicted
If you're convicted of drug driving you'll get:
- a minimum 1 year driving ban
- between 3 and 11 penalty points
- a fine of up to £5,000 and/or up to 6 months in prison
- a criminal record
Your driving licence will show you've been convicted of drug driving. This will last for 11 years.
You could go to prison for up to 14 years if you cause death by dangerous driving if unfit through drugs.
Other problems you could face
A drug driving conviction can also affect:
- car insurance costs
- current or future jobs
- travelling to countries such as the USA
- volunteering – especially with children or people with support needs