THE BLOG
11/03/2015 10:23 GMT | Updated 11/05/2015 06:59 BST

What Constitutes Drug Driving?

The purpose of this article is not to discuss the wrongs or rights of the new drug driving offence, but to consider how it is likely to play out in practice. After all, there is no point having a law that cannot be enforced or will cause difficulties with enforcement.

The new drug driving law is akin to the law we currently have on drink driving, introducing a new offence of driving while over the prescribed drug limit. The maximum penalty available for this is 51 weeks' imprisonment and a fine of £5,000 but there is also an obligatory disqualification from driving for a minimum of 12 months.

You may be wondering why it has taken so long for this new offence to be enacted. Well it is already an offence under section 4 of the Road Traffic Act to drive while impaired by drugs (or alcohol), and this will remain in place alongside the new offence.

The difficulty with the s4 offence is that it requires proof of impairment by virtue of the drugs (or alcohol) and this was often difficult to substantiate. By the time the police got the suspect to the police station to take a blood or urine test, the level of drugs would have reduced somewhat and the threshold is often too high to show impairment by virtue of the drugs (or alcohol). Unlike the section 4 offence, the new offence will not require proof of impairment.

Under the new offence there are legal limits of how much of a particular prescription drug you can have in your system, and, as far as unlawful drugs are concerned, they are completely prohibited unless they come within an exemption, such as certain unlawful drugs which are permitted for medicinal purposes. It will therefore be easier to prosecute offenders - or so it seems.

You can drive after taking certain prescription drugs if you have been prescribed them and provided you have followed the advice on how to take them by a healthcare professional and they aren't causing you to be unfit to drive even if you're above the specified limits. Therefore, you could be prosecuted if you drive with certain levels of these drugs in your body and you haven't been prescribed them. Even if you have a prescription and followed the advice given, if it is shown you are impaired despite this, you may not make use of the defence because you would fall foul of the s.4 offence for which there is no medical defence.

The problems with this new offence are that suspects/patients may be given the wrong advice by healthcare professionals, or they may 'say' they have been given the wrong advice. In either case, there will be issues of investigating the suspect and their healthcare professional. Inevitably, there will be cases where healthcare professionals will be forced to come to court to give evidence. Not a welcome thought for most people.

I am already sensing an even heavier caseload for the courts as a result of this new offence and the ramifications and time that it will take to fully prepare a case where the defendant pleads not guilty. Even trickier since I expect suspects who are on medication will have a long-standing relationship with their healthcare professional.

This new offence inevitably requires that guidance be given to healthcare professionals about how to give advice to patients and prescribe such medication. Indeed some healthcare professionals may well be concerned about prescribing the drug at all because of complications they face if they know someone may drive having taken it. Furthermore, it seems odd that the official guidance issued to healthcare professionals by the government in July 2014 seems to require 'them' to explain the offence to patients!

Much of the advice seems logical and it is likely that healthcare professionals were already giving this long before this new offence came into effect. For example, 'this drug has symptoms that cause drowsiness and as such you shouldn't drive or handle heavy machinery after taking it'. But it gets confusing because of the effect of other drugs or indeed drink on the medication.

Further complications arise if the patient takes any new medicines that are known to be able to affect the metabolism of their existing medicine and so might impair their driving or other relevant situations, such as the effects of age or the re-initiation of a medicine. It seems like quite a complicated approach for a healthcare professional.

If evidence is adduced to raise the defence, the court must assume that the defence is satisfied unless the prosecution proves beyond reasonable doubt that it is not. Quite a burden on the prosecution and police no doubt, given the issues set out above.

Drink driving offences are often straightforward, you're either within or over the limit. If you're over the limit, the only way you may avoid disqualification is to show special reasons, for example, that your drink was spiked. Special reasons cases take time as they require expert medical evidence and they obviously take up more court time than a straightforward guilty plea. The defence available to drug driving will also cause delays and increase costs. Legal Aid is limited for drink driving unless the level of alcohol is so high as to suggest an immediate custodial sentence. I expect legal aid will also be limited for this new offence. The government website actually states to healthcare professionals:

"A patient suffering with a condition that is being treated by a medicine that is also one of the specified drugs for the new offence, should normally still be encouraged to keep taking their prescribed medicine for that clinical condition in accordance with the advice of the prescriber or pharmacist. If the patient has been driving in line with such advice, and has no reason to think themselves impaired to drive (for example, not having developed new symptoms such as sleepiness), they can be advised that they will be entitled to raise the statutory "medical defence". "

So although the government seem to be saying don't worry to patients on prescribed drugs, and their medical practitioners, they won't be providing funding for patients to use the defence. Won't this lead to patients who have to drive, not taking their medication? This in turn has its own ramifications.