Professor Denis Cusack:

I will revert to the first question concerning what will change. At the moment, an intoxicant is defined in the 2010 Act as alcohol and drugs, and any combination of drugs or of drugs and alcohol. Therefore, it is not an entirely new concept. To put it into context, in 1998 when the bureau was still only dealing with blood and urine, there was no evidential breath-testing, so every sample was blood or urine. Out of about 15,000 samples only eight were tested for drugs. Last year, it was in the region of 1,200 of the blood and urine samples that came in, which is approximately one quarter of all the samples. Therefore, we are already testing quite extensively for it. This recognises, first, that it is an increasing problem and, second, that technology is now available which can assist in the recognition. I do want to stress, however, that at the moment we are only looking at the four classes - they are, cannabis, benzodiazepines, opiates and cocaine.

There will always be other drugs that we cannot currently, and maybe for some time into the future, assess at the roadside. That is why I would also like to put in context the fact that roadside impairment testing, for which thousands of gardaí have been trained and which was implemented last November, is still an important part of it.

The Chairman's question is one of great concern. If I were to speak as a forensic doctor or as an ordinary doctor, there would be different aspects. The last thing anybody wants to do is cause distress or worry to anybody who is on prescribed medication, or who goes to their supermarket or chemist and gets over-the-counter products for a headache, some of which contain codeine, paracetamol or caffeine. If somebody takes an awful lot of codeine it could show up as an opiate.

This is not about illegal or prescribable drugs, however, it is about impairment and safe driving. Therefore, whether or not somebody is taking a prescribable or prescribed drug and is impaired, they are no less of a danger to themselves and others. It is important to recognise that there are certain types of drug which have no legitimate medical use.

I had a look at my old-fashioned licence document and it does say that it is a driving licence or ceadúnas tiomána. It is a licence, not a right, so everyone who drives has to take care they are not tired, distracted, on medications or changed medications. If somebody is taking it in accordance with a prescription, including their pharmacist's or doctor's advice, I want to stress that we see this linking in with medical fitness to drive, not the misuse of drugs. Therefore, sláinte agus tiomáint is important for drivers. In general, they will not have anything to be worried about. However, if somebody changes their medication and feels groggy, they should not be driving. Where somebody is taking something that has no legitimate medicinal use, such as cocaine or heroin, by driving they are putting themselves and others at risk because of the known impairment effects.

That is why there is an attempt to differentiate between these things. Again, I need to be very careful, but this is not about misuse of drugs. It is another issue as to whether people should be using cocaine or cannabis socially or whatever. This is entirely about whether it is safe for a person to drive in respect of him or herself and in respect of others.

We need a very important campaign. This cannot be brought in without ensuring that there is a balance. People need to be told not to worry about their blood pressure tablets or to continue taking their diabetic treatment or epilepsy tablets. Whether in a GP surgery, a pharmacy or elsewhere, information on fitness to drive that people can rely on needs to be provided in simple, plain and understandable language. I have seen the equivalents in other countries because I am on the medical advisory panel for the Department for Transport in London. That is terribly important. I hope it answers the legitimate concerns.