Chapter 9. Medication Safety and Pharmacovigilance

At the end of the chapter, the reader will be able to:

1. Describe the major terms used in drug safety evaluation.

2. Describe two methods for categorizing adverse drug events.

3. Identify the major amendments to the Food, Drug and Cosmetic Act that address drug efficacy and safety.

4. Describe the ways that drug safety problems are identified pre- and post-market approval.

5. Discuss special considerations when considering the relative risk of adverse events.

Pharmacovigilance is the science relating to the detection, assessment, and prevention of adverse effects of medicines. As such, pharmacovigilance is primarily involved in the identification and evaluation of safety signals that are identified for drug products. Proper management of drug safety risks has always been a major concern in health care systems worldwide and among pharmaceutical manufacturers. In fact, major drug safety events have served as the stimuli for many of the major changes that have occurred in drug regulation in the United States and other countries. As a result, drug regulations have evolved over time to address our growing understanding of drug safety and the evolution of the pharmaceutical industry. During the past few decades it has been stated that a paradigm shift has occurred in the assessment and management of patient-related drug safety. Some of these changes, especially the most recent, have resulted in a significant increase in the importance of pharmacoepidemiology and its use in pharmacovigilance.

Some of the major changes during the past few decades have included:

• An evolution of the drug market from short-duration-use products used to treat acute diseases to long-term-use products for the treatment of chronic diseases.
• A change in attitude by regulators and industry from pre- and post-marketing safety assessment being viewed as separate activities to the assessment of product safety being a continuous process that starts early in product development and continues throughout the life of a marketed product.
• A shift from postmarketing safety assessment relying almost solely on individual case reports from practitioners and clinical trials to a modern system using large quantities of information collected by a number of different computerized systems (i.e., administrative claims data, electronic medical records) for both active surveillance and evaluation of safety signals.
• An increased use of retrospective pharmacoepidemiologic studies to evaluate safety signals.
• Increased prescription product litigation and the need to better manage the understanding of drug risks by practitioners and the public.

As a result of these changes and the possible paradigm shift, pre- and post-marketing safety surveillance, which were once viewed as separate activities, are now viewed as a continuum of “risk management” activities for pharmaceutical manufacturers, drug safety regulators, and health care providers. In the United States, assuring the safety of drug products is the responsibility of the Food and Drug Administration (FDA). According to the FDA Guidances for Industry,1 risk management is an iterative process designed to optimize the benefit–risk balance for regulated prescription drug products. A brief history of ...