Can I be charged with drug driving after taking prescription medication?

If we told you that taking prescription medication can still result in a drug driving charge in the UK, would you be surprised?

It’s a misconception that only illegal or recreational drugs can lead to a drug driving charge. In fact, the law is clear. If you are a driver in England, Scotland or Wales, you can be charged with drug driving even when taking legally prescribed medication. This law incorporates prescription drugs such as codeine, diazepam and morphine in order to keep our roads safe.

There is such a thing as a ‘medical defence’ – that is, a legitimate medical reason that allows a driver to avoid a conviction if they are over the legal limit for the drug in their system – but this does not offer blanket protection.

So let’s look in more detail at the scenario of being charged with drug driving after taking prescription medication.

When can you be charged?

You may face a drug driving charge if the police believe that:

Your driving is impaired

If officers observe unsafe driving such as erratic behaviour, substandard lane control, and careless or inconsiderate driving.

You are over the legal limit

Some prescription drugs have legally defined blood limits. If a blood test shows that the level of a drug exceeds the threshold, you can be charged.

You did not follow instructions

This may include taking more than the prescribed dose, or mixing medication with alcohol.

The ‘medical defence’

The law recognises that some people need medication to function on a daily basis. If all of the following criteria apply, you may avoid conviction:

1. The medication was prescribed to you for a genuine medical or dental condition.
2. You took it exactly as instructed by your doctor, pharmacist, and the patient leaflet.
3. You were not advised by a healthcare professional to avoid driving.
4. Your driving was not impaired.

Be clear that if impairment is found, the medical defence may not apply, even if the drug has been taken correctly.

Penalties for conviction

Drug driving convictions, including those which resulted from a driver taking prescription drugs, carry serious consequences. Penalties for conviction may include:

• A minimum 1-year driving ban
• An unlimited fine
• Up to 6 months in prison
• A criminal record, with the offence staying on your licence for 11 years

If you take prescription medication, always follow the instructions carefully and speak to your doctor or pharmacist if you’re unsure whether it’s safe to drive.