Adverse drug event surveillance and drug withdrawals in the United States, 1969-2002 - The importance of reporting suspected reactions

Background: The Adverse Event Reporting System is the primary surveillance database used by the Food and Drug Administration for identifying postmarketing drug safety problems. Methods: We analyzed all reports of suspected adverse drug reactions submitted to the Food and Drug Administration from the inception of the Adverse Event Reporting System database in 1969 through December 2002. We documented drug withdrawals and restricted distribution programs based on safety concerns. Results: During the 33-year period from 1969 when adverse drug event reporting was initiated through 2002, about 2.3 million case reports of adverse events for the cumulative number of approximately 6000 marketed drugs were entered in the database. Most reports were for female patients. During this period, numerous drug reactions have been identified and added to the product labeling as boxed warnings, warnings, precautions, contraindications, and adverse reactions. More than 75 drugs/drug products have been removed from the market due to safety problems. In addition, 11 drugs have special requirements for prescriptions or have restricted distribution programs. Drugs withdrawn or restricted represent a small proportion (about 1%) of marketed drugs. Conclusions: The Food and Drug Administration's Adverse Event Reporting System is the primary surveillance database used for the identification of safety problems of marketed drugs. Despite the limitations of underreporting, differential reporting, and uneven quality, submitted reports often allow the identification of serious adverse events that are added to the product labeling information. In rare instances, additional regulations, up to and including market removal, have been required. We encourage physicians, pharmacists, other health care professionals, and patients to continue to report serious suspected and known adverse drug reactions to manufacturers and the Food and Drug Administration.