Author
Dr. Nigel SB Rawson, Ph.D.
Introduction
In a recent article published in the journal Open Medicine (“How safe are new drugs? Market withdrawal of drugs approved in Canada between 1990 and 2009”), author Joel Lexchin examined the issue of drug safety in Canada finding that 22 drugs had been withdrawn from the Canadian market for safety reasons between 1990 and 2009. Lexchin suggested that Health Canada is too quick to approve new drugs, and raised doubts about the rigour of the drug safety evaluation and surveillance system in Canada.
Objective
To re-examine the evidence on which Lexchin’s conclusions are based, as well as other relevant empirical evidence.
Data
Data for this article come from a database of new drugs introduced in Canada and the United States between 1992 and 2011 developed over the past 20 years from information from Health Canada, the US Food and Drug Administration and pharmaceutical companies, and other analyses.
Results
Submission and approval dates and review times were available for 17 of the 22 drugs examined by Lexchin. Contrary to Lexchin’s claims, there is no evidence that Health Canada approved the 17 drugs that were withdrawn for safety reasons more rapidly than other drugs that were not discontinued from the market. In fact, all 17 drugs had review times that exceeded Health Canada’s performance targets. Further, analysis of new drugs approved in both Canada and the United States between 1992 and 2011 shows that many drugs are approved in Canada significantly later than in the United States, yet longer approval times are not associated with better statistics on drug safety: the proportion of approved drugs that were subsequently discontinued for safety reasons was the same in both countries. Also contrary to Lexchin’s claim, the increased number of reports on adverse drug reactions (ADRs) over the past 10-15 years does not necessarily imply an increase in actual ADRs over time. Health Canada has been constantly urging the reporting of suspected ADRs during this period, and has introduced methods to simplify and increase reporting; therefore the data could be simply reflecting an improvement in the data collection system.
Conclusions
There is no evidence to indicate a lack of rigour in Health Canada’s drug safety review and monitoring systems.
