Postmarketing Surveillance of Drugs: An Overview

Abstract

The complete safety profile of a drug cannot be made before marketing because of the limited scope of the controlled clinical trials. Postmarketing surveillance (PMS) is the collection and analysis of information about a drug after it has been marketed. A PMS system ideally must be able to detect a rare event, determine its incidence, and validate the causality. Because an ideal system has not been devised, a combination of methods is used. The advantages and limitations of various methods of adverse drug reaction (ADE) reporting are described, and problems and concerns associated with ADE reporting are discussed. Postmarketing surveillance will continue to benefit from spontaneous reporting of ADEs by clinicians (ie, literature reports, reports to manufacturers and national regulatory agencies) to detect rare events and will be complemented by the selective use of formal PMS methods in appropriate circumstances. Increased clinician awareness of serious, potentially drug-related events together with comprehensive and complete reporting of these events will begin to address the problems of underreporting, assessment of causality, and misclassification of events.