Dr. Peter Widdess-Walsh:

I thank the joint committee for the opportunity to speak. I have been an epilepsy specialist for almost nine years and have treated hundreds of people with epilepsy and share Mr. Glynn's view and concerns about generic substitution of anti-epileptic drugs. It is a specific class of drugs that should be protected. In the case of other medications such as, for instance, cholesterol or blood pressure medications, a couple of points in difference might not make too much difference. However, when one is talking about the chemistry of the brain, where even a slight alteration in brain chemistry in a patient with epilepsy can result in destabilisation of the epilepsy and seizures, this is a major concern. Epilepsy is common and we think there is a prevalence of approximately 1%, or one person in 100 in western populations, which means it will affect every community in Ireland. A patient with epilepsy who lives down the road and who gets a generic substitution will have a higher risk of having a seizure which, by its very nature is unpredictable and could occur at any time including when such people are behind the wheel or when there are kids crossing the road. Consequently, there is both major concern for the patients themselves and a certain public safety concern.

As for answering some of the medical questions, I refer to the risk of death from epilepsy. While we do not have exact figures on sudden death related to generic substitution, we do know that sudden death in epilepsy is much more common than in the general population. It is at least twice the risk of that which obtains in the general population and for patients who have more delicately controlled or difficult to control epilepsy, the risk is up to 20 or 30 times for sudden death when compared with a general population risk. Consequently, we would expect to see some increased risk of death on foot of destabilisation. In addition, studies have shown specifically after generic substitution that there have been increases in injuries and seizure-related complications, which have then required a switch back to the brand. There are studies showing high rates of switching back from generic to brand for anti-epileptic drugs as opposed to many other studied classes of medications.

As for the 20% to 30% change to which reference was made, these are pharmacological parameters and there can be relatively wide variations in such pharmacological parameters between different generics. For a single drug, one could have up to 20 to 30 different generic formulations and again, a patient could get any particular one of those generic formulations when they go to the pharmacy on that particular month. It is of major concern that there can be such a wide variation. This number, when it boils down to actual absolute changes in the concentrations of medications in the body, would be in the order of 3% to 5%. However, from our perspective these still are huge numbers in respect of those chemistry changes in the brain that can result in destabilisation of the epilepsy.