Industry influence and Health Canada's responsibility: lessons from the opioid epidemic in Canada

Misleading claims that appeared in the OxyContin product monograph, which understated the risks associated with the drug, were used by Purdue in its promotional practices. The time it took for Health Canada to revise the monograph may have contributed to the over-prescription epidemic in Canada. The opioid epidemic is not only a United States problem. Canada is experiencing one of the worst public health crises in recent years, with more than 10 300 opioid-related deaths between January 2016 and September 2018 1. Why is Canada, whose health-care policies are different from those in the United States and are, in many aspects, similar to those in other countries without opioid epidemics, experiencing such a severe crisis? Similar to the United States, excessive prescription of opioids is recognized as a major factor leading to the crisis 2. Canada is second only to the United States globally in opioid prescription rates 3. For example, a recent study found that Canada and the United States have a seven times higher rate of opioid prescriptions filled after routine surgeries compared with Sweden 4. Purdue Pharma's introduction of OxyContin in the mid-1990s, and the aggressive marketing that followed, are considered to be an important contributing factor for the over-prescription of the drug in North America 5-7. Evidence suggests that Purdue Pharma Canada used misleading marketing claims—similar to those in the United States—that influenced opioid prescribing practices 5. For example, a pain management book, funded and copyrighted by Purdue, categorized oxycodone among weak opioids. 1 The book was distributed free of charge to doctors and health professions students at the University of Toronto, between 2004 and 2010, as part of a mandatory week-long curriculum on pain management 8. In April 2018, a group of Canadian physicians and opioid experts wrote a letter to the Federal government asking for a criminal investigation against Purdue for making misleading claims about the drug 9. Proximity to the United States and the close relationship between the academic medical communities may have also contributed to opioid over-prescription in Canada, as key American ‘opinion leaders’, crossed the border and promoted the safety of opioids in pain management seminars sponsored by Purdue 10. Furthermore, Canadians are exposed to US advertisements through US media and are influenced by US promotional materials 7. Thus, misleading promotions of OxyContin in the United States may have also influenced Canadians 5. Another contributing factor to the over-prescription in Canada may have been misleading information that appeared in the product monograph of OxyContin, which understated the risks associated with the drug. Approved by Health Canada, product monographs contain recommendations for health professionals (e.g. physicians, nurses, dentists, pharmacists) regarding the appropriate use of a drug and thus are likely to influence prescribing behaviour. Drug companies are permitted by law to use Health Canada-approved information in their marketing practices. Thus, if the information in the monograph is inaccurate, stating for example that a drug is safer and more effective than it is, pharmaceutical companies can use this information to influence physicians’ behaviour. Evidence from the United States shows that Purdue used the information that appeared on the original OxyContin label as an important selling point to influence physicians to prescribe opioids 11. When Health Canada approved OxyContin in 1996, it stated in the drug's product monograph, based on little evidence 6, that the drug was safe and effective for chronic pain. The product monograph included the sentence: ‘Drug abuse is not a problem in patients with pain in whom oxycodone [the active ingredient of OxyContin and the generic name of OxyContin] is appropriately indicated’ 12. This sentence appeared in the company's promotional practices 13. Furthermore, no recommended maximum dose was provided, allowing the drug to be marketed with no upper dose threshold 14. In July 2001, a steep increase in reports of addiction, abuse and deaths from OxyContin in the United States prompted the Food and Drug Administration (FDA) to revise the OxyContin label, deleting claims about low risk of addiction and abuse and adding a ‘Black Box Warning’ to the drug's packaging (the strongest type of warning the FDA can add to a drug) 11, 15, 16. The FDA also issued a warning to physicians, informing them about the risks and encouraging them to be more cautious when prescribing the drug 16. The FDA's action was known to the Canadian regulator—Health Canada 15. This agency closely follows decisions that are made by the FDA and treats the FDA as a reliable source of information for monitoring drugs for safety problems 17, specifically with regard to prescription drug abuse 18. However, in response to the FDA's label revision and the Black Box Warning, Health Canada decided that no similar action was needed in Canada 15. The agency may have believed that the OxyContin-abuse problem was limited to the United States, based on data from two drug report searches conducted in May and July 2001 that found no adverse drug reports involving OxyContin 15. Only in 2006, 5 years after the FDA's label revision and Black Box Warning, when the OxyContin problem became apparent in Canada, did Health Canada revise the drug's monograph. The agency strengthened the warning on how to take the pill, stated the danger of breaking, chewing or crushing the pills, and slightly changed the misleading sentence regarding the abuse liability of the drug, adding the word ‘usually’ in the sentence: ‘Drug abuse is usually not a problem …’ 19. Health Canada's delayed response allowed Purdue to use the misleading information in its promotional materials for more than 10 years (1996–2006). Two key lessons can be learned from the Canadian opioid prescription epidemic. First, drug companies’ strategies to influence the medical community should be a matter of significant public health concern. Identifying the means of regulating problematic relationships between pharmaceutical companies and the medical profession could help prevent similar crises in the future. Secondly, misleading claims in drugs’ labels should be rapidly updated as new information becomes available. A formal inquiry investigating the evidence behind the original product monograph for OxyContin and why Health Canada did not follow the FDA's decision in 2001 to change the label of the drug could shed new light on some of the factors leading to the opioid crisis in Canada. None.

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