Since the beginning of the Canadian adverse drug reaction monitoring program, CADRMP, in 1965, 155,000 domestic suspected adverse reaction reports have been received and entered into one of several databases used over this period of time.
There are more than 20,000 drug products approved and marketed in Canada. Product and company information, including the date of market notification, for these drugs is contained in Health Canada’s drug product database. Some of the information in the database is available through the Health Canada website.
The date of receipt of adverse reaction reports is included in the adverse reaction database maintained by Health Canada. Due to the volume of suspected adverse reaction and medication incident reports, the database does not link to actions in response to each report of suspected reaction. Moreover, actions in response to suspected adverse reaction reports usually follow detection and confirmation of a new signal or trend concerning a safety issue associated with a marketed drug or other health product as discovered by creating a series of case reports. In other words, a market intervention or action is taken once a sufficient level of scientific evidence from case reports of suspected adverse reactions or medication incidents has been received.
Adverse reaction reports to marketed health products are considered to be suspicious, as a definite causal association often cannot be determined. In some cases the reported clinical data may be incomplete, or the given reaction may be due to the underlying disease or to another coincidental factor. Signals may be identified through the systematic review of adverse reaction reports and any other additional information on product safety.
Potential signals need expert evaluation before more actions are undertaken. Actions must be based on scientific analysis of case series and this implies an evaluation of the signal and the appropriate benefit-risk review of the information available. Actions may vary depending on the nature, the seriousness and the frequency of the reaction, as well as on the intended use of the health product, the benefit obtained from its use versus the risks and the availability of alternative therapies.
Information concerning regulatory actions taken in response to submitted suspected adverse reactions and medication incidents is available on the Health Canada website. Health Canada posts advisories, Dear Health Care Professional letters, summary fact sheets and “It’s Your Health” issues on the Health Canada website. Health care professionals and consumers can subscribe to the Health_Prod_ Info electronic mailing list to receive timely safety information and notification of regulatory actions.
Since 1991, the Canadian adverse reaction newsletter has also summarized case reports of suspected adverse reactions and medication incidents and provides additional information regarding regulatory actions. For example, in the period from June 2001 to February 2002, 32 advisories for health professionals and consumers concerning drugs and health products have been posted on the Health Canada website.