Like many everyday medicines, your driving ability may be reduced (driving impairment) while you are taking your medical cannabis. Your medication may cause drowsiness and can initially reduce your reaction times. This can increase your risk of having an accident, putting yourself and others at risk.
You only need to inform the DVLA if you have a notifiable medical condition or disability that could affect your ability to drive safely. You do not need to inform them about your prescription. The only condition that medical cannabis is commonly prescribed which requires an individual to inform the DVLA is epilepsy.
A statutory defence may apply if a car accident occurs where a specialist doctor has legally prescribed medical cannabis and driving performance was not impaired.
The current legal limit for blood tetrahydrocannabinol (THC) levels is 2 micrograms/L. It is highly likely that if you have been prescribed medical cannabis preparations containing THC, you will exceed this limit.
THC can show up in your blood within minutes after taking your medication. THC is also stored in fat cells and is slowly released. This means that THC can still be detectable in your bloodstream well beyond 28 days.
No matter your medication, you should never drive whilst impaired. Your dose and prescription can affect you differently from someone else, so you should always speak to your specialist doctor about possible impairment while taking your medication. Cannabidiol (CBD) only products have been shown to have no potential effect on driving reaction speed and risk of collision.
