With more than 3.6 billion prescriptions being dispensed annually in the United States, it is clear that Americans are using more prescribed medication than at any other time in history.1 In addition, the use of nonprescription medication, including alternative medicines, is growing rapidly. While this increased medication use is due to a variety of reasons, including an aging population, the availability of many more effective drugs for myriad chronic diseases, and the desire to prevent disease, it can lead to unwanted adverse events (AEs), even as they provide great benefit.
It has been estimated that AEs cost the health-care system several billion dollars due to excess morbidity and mortality. However, the benefits of pharmaceutical products should not be minimized, as they can save the health-care system billions of dollars by changing the course of disease and disease management (e.g., decreased disability, less surgery, etc.).
Medication-related AEs occur frequently and while all of these AEs cannot be prevented, improving processes is the only way to improve quality.2 Unfortunately, health care lags behind other high-risk industries in its attention to ensuring basic safety. There is a need to identify and learn from errors through mandatory reporting efforts. The Institute of Medicine has called for a nationwide mandatory reporting system to be established, and the data received should be analyzed to identify safety issues that require a broad-based response.2
From 2000–2005, there were 11 drug withdrawals for safety reasons in the United States.3 The regulatory agency that is responsible for postmarketing safety surveillance (PMSS) in America is the Food and Drug Administration (FDA). As such, the FDA reviews reports of adverse drug reactions from studies and from PMSS reports. While the FDA has the authority to withdraw the approval of a drug, in all of these cases, the drug's sponsor voluntarily withdrew the drug from the market. However, the FDA has been criticized for not acting quickly enough on evidence it obtained, and informing physicians and patients about safety issues concerning some of these drugs that were subsequently withdrawn from the market.4 Because no drug is absolutely safe—there is always some risk of an adverse reaction—the FDA's approval of a drug for marketing is contingent on its continued assessment of that drug's risks and benefits.4
This chapter will review the current U.S. PMSS process, describe the MedWatch program, and discuss the types of AEs that exist along with their reporting requirements. It will also show how AE reporting, along with analysis of those case reports, utilizing techniques such as data mining, can lead to signal detection and drug withdrawals as necessary, to protect the public health.
PMSS is the process for monitoring all marketed pharmaceuticals and medical devices to ensure timely identification, evaluation, and communication of any new or unexpected adverse reactions or safety concerns.5...