Knowledge Hub

Despite medical cannabis being legal in the UK for almost six years, confusion and mixed messages persist regarding patients' rights and responsibilities when driving with their prescription. This article examines the DVLA guidance around prescription medications, including medical cannabis, and explores patients' rights on the road.

Prescription Medication and Driving

What is the role of the DVLA?

The Driver and Vehicle Licensing Agency (DVLA) is an agency of the Department for Transport (DfT), which plays a crucial role in ensuring the safety and regulation of drivers and vehicles in the UK. The main responsibilities of the DVLA include:

• Recording driver endorsements, disqualifications, and medical conditions
• Issuing photocard driving licences
• Issuing vehicle registration certificates to vehicle keepers
• Taking enforcement action against vehicle tax evaders
• Registering and issuing tachograph cards
• Selling DVLA personalised registrations
• Helping the police and intelligence authorities deal with crime
• Providing anonymised data to those who have the right to use the service

What medication do you need to declare to DVLA?

In the UK, if you are taking certain medications that could affect your ability to drive safely, you may need to declare them to the DVLA. This requirement usually applies if the medication impacts your ability to drive safely, or if you have a medical condition that requires notification and the medication is related to that condition.

This includes illegal drugs, but also medications that may be prescribed for conditions such as epilepsy, diabetes, heart conditions, neurological and psychiatric disorders.

Some examples include: Amphetamines, clonazepam, diazepam, flunitrazepam, lorazepam, methadone, morphine, opiates and opioid-based drugs, anti-psychotics.

Drivers are advised to consult their doctor or pharmacist if they are unsure whether a medication might affect their driving.

What medical conditions must be reported to the DVLA?

If you hold a UK driving licence, the law states that you must tell the DVLA if you develop a ‘notifiable’ medical condition or disability, or a condition or disability has got worse since you got your licence. Notifiable conditions are classed as anything that could influence your ability to drive safely.

• Diabetes or taking insulin
• Syncope (fainting)
• Heart conditions (including atrial fibrillation and pacemakers)
• Sleep apnoea
• Epilepsy
• Strokes
• Glaucoma

Failing to declare a notifiable medical condition can lead to fines, penalties, or even prosecution if you are involved in an accident and found to be driving against medical advice.

Driving while on medication

The DVLA guidelines require patients to be “free from any medication effects that would impair driving” as a condition for continuing to drive or resuming driving following medication. The elements required for safe driving include: attention and concentration, good reaction time, and coordination.

Drivers must not drive if they feel that their medication impairs their ability to do so safely. This includes any medication that causes drowsiness, dizziness, blurred vision, or delayed reaction times.

Driving and Medical Cannabis

Medical cannabis driving laws

In the UK, the law is clear that it is illegal to drive while impaired by any drug, including cannabis, whether it is prescribed for medical use or not.

However, driving legislation was not amended in any way following the legalisation of medical cannabis back in 2018. Unfortunately, current drug driving tests—combined with a lack of awareness around the legality of medical cannabis—has resulted in reports of patients being arrested and charged despite not being impaired at the time of driving.

Can I drive with a cannabis prescription in the UK?

Yes, you can possess and take your medicine and continue to drive a motor vehicle, as long as the following requirements are met:

• You are not impaired
• The medication has been prescribed by a specialist consultant and you can provide evidence of this
• You are following the instructions provided by your consultant, as well as the manufacturer or distributor of the medicine.

The law expects drivers to be aware of how their medication affects them. If you feel drowsy, dizzy, or otherwise impaired after taking medical cannabis, you should not drive.

Do I need to tell the DVLA about medical cannabis?

There is no clear guidance from the DVLA specifically on medical cannabis. And, nowhere does it state that patients are required to inform them of their prescription, unless it's related to a notifiable condition which may impact your ability to drive safely.

How Does Cannabis Affect Driving?

THC, the main psychoactive compound found in cannabis can cause effects which may impact driving ability. These include, drowsiness, impaired judgement, slower reaction time, poorer control of motor skills, lack of concentration, confusion and blurred vision.

While THC levels may impact on the nature and level of impairment, CBD is not generally regarded as a concern for road safety, with research showing that even high doses do not affect driving impairment.

Cannabis limit for driving UK

The law sets specific blood concentration limits for certain drugs, including THC. In the UK, the legal limit for THC while driving is 2 micrograms per litre (μg/L) of blood. This is generally considered a low threshold, reflecting the law’s ‘zero-tolerance’ approach. If you exceed this limit, you can be charged with drug driving, even if you are taking the drug legally with a prescription.