As reported by Wayne Kondro,1 Health Canada's February 2005 decision to withdraw Adderall XR (a mixture of 4 amphetamine salts marketed by Shire Biochem for the treatment of attention deficit hyperactivity disorders [ADHD]) was reversed in August by a 3-member New Drug Committee. Stronger labelling has been recommended, and sudden death, myocardial infarction, cerebrovascular accident and convulsion will be added to the list of adverse drug reactions.
This situation raises a number of disturbing questions. Given that Adderall XR was approved by Health Canada after deaths and other problems had been reported to the US Food and Drug Administration, it must be asked whether Health Canada had those reports when it approved the drug. If so, why did approval go ahead? If not, why did it apparently take more than a year for Health Canada to acquire the reports? There is a lack of evidence that Adderall XR is clinically superior to other stimulants used to treat ADHD, the New Drug Committee found that higher risks of sudden cardiac death have “not been ruled out due to limitations in the data currently available,”2 and there is clear evidence of underreporting of serious adverse events. Given these problems, what is the Canadian public to make of the decision to reintroduce Adderall XR?
The reliance on stronger labelling also raises questions. In the United States, stronger labelling for another ADHD drug, pemoline (Cylert), was ineffective in ensuring safe use.3 In this type of situation, the precautionary principle — had it been heeded — would have provided clear guidance. With no additional health benefits and reasonable suspicion of harm, public health concerns should trump economic interests, yet the New Drug Committee appears to have decided otherwise. To what extent does this reflect the committee's terms of reference and process? The committee met in private and reviewed only data that had been provided by Shire and Health Canada. The committee's mandate appears not to have included issues such as the imprecise diagnosis of ADHD, evidence of overdiagnosis of the condition in North America, and whether a net public health benefit was expected from reintroduction of this amphetamine product.
Why are the scientific data that form the basis of regulatory decisions in Canada considered proprietary? The New Drug Committee should have met in public, its reports and transcripts should have been posted on the Web, and other scientists, health care professionals and members of the public should have been allowed to make submissions. The committee's report provides a glimpse of the thinking behind regulatory decision-making. A glimpse is not enough: full participation and access to information are needed.
Footnotes
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Competing interests: None declared.