Case Study: Drug Driving Charge Dropped - Lawful Medicinal Cannabis Use Successfully Defended

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The Situation

Our client was stopped by police and later charged with drug driving after a blood test revealed 13 micrograms of cannabis (THC) in his system - a level which, in many cases, would automatically lead to prosecution and a driving ban.

However, this was not recreational drug use.

Our client was a lawful medicinal cannabis patient, prescribed cannabis by a qualified medical professional to manage a long-term medical condition.

At the roadside and during custody, the client informed officers that he was prescribed medicinal cannabis and was using it in line with medical advice. Despite this, proceedings were still initiated. A situation becoming increasingly common as prescriptions rise across the UK.

The Growing Issue of Medicinal Cannabis & Drug Driving Charges

Since medicinal cannabis became legal in the UK for medical use, thousands of patients now rely on prescribed cannabis for conditions such as:

  • Chronic pain
  • Anxiety and PTSD
  • Neurological conditions
  • Sleep disorders

However, many police investigations still treat the presence of THC in blood results as automatic guilt, without properly considering the legal medical defence available to prescribed patients.

This has led to a sharp increase in lawful patients being wrongly charged.

The Key Legal Defence

UK drug driving law provides a clear statutory medical defence where:

✔️ The drug has been lawfully prescribed or supplied
✔️ The patient takes it in accordance with medical instructions
✔️ Possession is lawful
✔️ There is no evidence of driving impairment

Crucially:

⚠️ The presence of THC alone does not prove an offence
⚠️ Prosecution must show impairment or unlawful use

This distinction is frequently misunderstood by both drivers and authorities.

Our Defence Strategy

This case was led by Phoebe (Trainee Solicitor) and Jack (Paralegal).

Together, they built a robust defence by carefully assembling:

  • Proof of the client’s lawful medicinal cannabis prescription
  • Medical documentation confirming correct usage
  • Expert evidence explaining how prescribed cannabis could result in the reported THC level
  • Custody records and police footage confirming disclosure of prescription
  • A full review of whether any impairment evidence existed

Importantly, there was no evidence whatsoever that the client’s driving was impaired.

Phoebe and Jack prepared comprehensive written representations to the CPS clearly outlining:

👉 The statutory medical defence applied in full
👉 The client had acted lawfully at all times
👉 The prosecution could not meet the legal threshold required for conviction

The Outcome

Following a full review of the evidence and legal submissions, the CPS accepted that the charge could not proceed.

The drug driving prosecution was formally withdrawn.

Our client avoided:

✅ A mandatory driving ban
✅ A criminal record
✅ Serious financial, employment and insurance consequences

Why This Case Is So Important

This case highlights a major issue currently facing medicinal cannabis patients across the UK.

Many lawful drivers are being prosecuted simply because THC is detected, even where:

✔️ The medication is prescribed
✔️ It is used properly
✔️ There is no impairment

Without specialist motoring law representation, many of these cases would result in wrongful convictions.

The MAJ Law Difference

Medicinal cannabis defences are highly technical and require specialist knowledge of both motoring law and medical evidence.

At M.A.J Law, we routinely challenge:

  • Unlawful prosecutions
  • Misinterpretation of blood results
  • Failure to apply the medical defence
  • Lack of impairment evidence

Our approach focuses on stopping cases early and protecting clients before court becomes necessary.

Facing a Drug Driving Charge While Prescribed Medicinal Cannabis?

If you are a lawful medicinal cannabis patient, you may have a full legal defence, but these cases must be handled correctly from the outset.

Early legal advice can be the difference between conviction and withdrawal.

For more information, see our full blog on Medicinal Cannabis Defences