Thank you for the question.
It's important to point out that with any medication, after it is market-authorized, there is increasing exposure to the drug as more and more patients use it. In clinical trials that were done to prove the therapy, there may have been slight signals of a concern. As you get greater exposure, you learn more, so the neuropsychiatric side effects associated with mefloquine became better defined and better described as use persisted.
We see that globally in the labelling of the product in many countries increasing from a warning of “don't prescribe it to people with neuropsychiatric problems”. We started to see that a small number of people who, before starting the drug, did not apparently have neuropsychiatric problems developed these while on the drug. Not only should it not be given to people who have pre-existing problems, but in a very small number of individuals without a history, we were getting reports that it actually induced neuropsychiatric problems, some of them severe. That's why the labelling got tighter and tighter.
I agree that there should be research. It's a very important area to explore. The question is who is best positioned to do that? The role of Health Canada is to monitor each drug and the information we have on it, and to make sure it's labelled. If it reaches a point where the benefit-risk profile is not positive, then we will take affirmative action. At this point, as signalled by its still being listed as one of the choices to treat falciparum malaria in chloroquine-resistant areas, the profile is not that severe. But we would support and encourage additional research into this area, absolutely.