The FDA carefully considers all the available safety information submitted to the agency before a product is approved. However, unexpected and sometimes serious safety problems can emerge once a product goes to market and is used by millions of people.
As a result, postmarket safety monitoring, that is, analyzing information on products once they go to market, is a critical part of the FDA’s responsibilities.
The public provides an important source of such safety information. Health care facilities, practitioners, and patients submit reports to the FDA and to manufacturers on adverse events, medical errors, and product quality problems observed during the use of a product. Reporting by facilities, practitioners and patients to the FDA or to manufacturers – known either as voluntary reporting when involving medical devices and spontaneous reporting when involving drugs and biologic products – is entirely voluntary and has increased greatly in recent years. In addition to voluntary reporting, there is mandatory reporting. Manufacturers who receive a report must submit it to the FDA and healthcare facilities must file reports of deaths and serious injuries involving medical devices.
Reports to the FDA are sent to the agency’s MedWatch program or to the Vaccine Adverse Event Reporting System for vaccines. MedWatch also provides an Internet gateway for finding safety information about products.
The FDA analyzes both voluntary and mandatory reports to develop hypotheses about possible adverse events. In many cases it is hard to know whether an adverse event that happens after taking a drug was caused by the medication itself because many adverse events such as stroke or heart attack can occur from other causes, such as a patient’s underlying illness. But where the adverse event is very uncommon and unanticipated and the event occurs soon after the drug is started, there may be good reason to think the drug caused the adverse event.
Sometimes there is a need to conduct new studies to determine whether or not an adverse event associated with the use of a medical product was in fact caused by that product. The spontaneous reporting system is still the principal mechanism by which signals of such rare, but serious, adverse events are currently detected.
The results can be powerful: Reports of severe and in many cases fatal liver injuries resulted in the market removal of the nonsteroidal anti-inflammatory drug Duract (bromfenac) in 1998 only months after its approval. Similarly, the FDA received four reports of a serious condition affecting the bone marrow within four months after the antibiotic Zyvox (linezolid) was approved for marketing in 2000. The label was revised to inform providers about the risk for this adverse reaction and with recommendations for monitoring patients.
Safety reports about devices are also helpful. Just one report that a patient had become paralyzed following surgery on a cracked rib resulted in an important labeling change for a product used to stop bleeding where the rib connected to the spinal column. It turned out that the product could swell and put pressure on surrounding tissue, damaging the spinal cord.
Physicians at four different institutions across the United States informed the FDA about an increasing number of severe and life-threatening complications associated with metallic stents used to prop open the trachea. In response, the FDA sent out an alert to other health care practitioners. The alert warned about the risk of this complication in patients with a certain type of breathing disorder.
The bottom line: voluntary and mandatory reporting plays an important role in the FDA’s postmarket safety monitoring.