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Understanding CDER’s Postmarket Safety Surveillance Programs and Public Data

FDA maintains a system of postmarket surveillance and risk assessment programs to identify and evaluate adverse drug reactions and medication errors that did not appear during the drug development process, and to learn more about known adverse drug reactions. As part of this effort, the agency receives and analyzes reports of adverse events – problems that patients have after they take a drug regardless of whether the drug caused the event or not – to determine if these adverse events were caused by a drug. CDER uses these reports, along with other sources of drug safety data, to monitor the safety of approved drugs and therapeutic biologic products. When new potential safety issues are identified, FDA conducts a thorough and rigorous review of the available data before determining what, if any, actions are appropriate.

In this CDER Conversation, Gerald J. Dal Pan, M.D., M.H.S., Director of CDER’s Office of Surveillance and Epidemiology (OSE), discusses current priorities to develop and implement processes needed to support efficient and effective postmarket safety.

How does CDER monitor safety issues after a drug’s approval and what does FDA do when a safety issue is identified?

Gerald J. Dal Pan, M.D., M.H.S. Headshot photo
Gerald J. Dal Pan, M.D., M.H.S.

It is important to understand the difference between an adverse event and an adverse drug reaction. An adverse event is any unexpected medical occurrence in a patient administered a medicine, which does not necessarily have a causal relationship with this treatment. An adverse drug reaction, on the other hand, is a harmful and unintended response to a medicine – that is, it is an adverse event that is caused by a drug.

Our FDA Adverse Event Reporting System (FAERS) database, which contains adverse event reports, medication error reports, and product quality complaints submitted to the agency, is one of the main tools that supports our postmarket safety surveillance program. Because the reports in FAERS are reports of adverse events, one cannot assume that these events were caused by a drug. CDER health care professionals with special expertise in drug safety carefully monitor the FAERS database and, together with medical and scientific experts from multiples disciplines, determine whether they represent adverse drug reactions.

Another key component of FDA’s safety surveillance program is the Sentinel System, which uses real-world data on medication usage and medical diagnoses of over 300 million people in the United States to generate evidence about adverse drug reactions. These data, which come from administrative claims databases and electronic health records, provide FDA with “active surveillance” capabilities that are an important complement to FAERS data.

When CDER staff identify new information about the safety of a drug, we investigate the issue and consider appropriate action, which may include requesting or requiring changes to the drug’s Full Prescribing Information (also known as the drug’s labeling or package insert), issuing a public communication such as a Drug Safety Communication, requiring companies to conduct postmarket safety studies, requiring or modifying a Risk Evaluation and Mitigation Strategy (REMS), or, rarely, requesting a market withdrawal of the drug.

Additional information on how FDA approaches safety surveillance can be found in Best Practices for FDA Staff in the Postmarketing Safety Surveillance of Human Drug and Biological Products.

Can you explain any data limitations in the FAERS Public Dashboard?

The FAERS Public Dashboard is an interactive web-based tool that allows the public to search for information related to adverse events reported to FDA by drug companies, health care professionals, and consumers. However, the data in the FAERS Public Dashboard alone do not provide the full picture of the safety of a drug and should not be used to determine the safety profile of one drug compared to another.

The FAERS Public Dashboard does not contain all the data fields our safety staff have access to. These additional data fields, such as a narrative description of the adverse event, are not publicly available to protect patient and reporter privacy. To effectively analyze the safety data FDA has, CDER’s clinical reviewers need to review these additional data fields to remove duplicate reports, apply case definitions (e.g., a set of uniformly applied criteria for determining whether a person should be identified as having a particular disease, injury, or health condition), and assess if a drug caused an adverse event. What constitutes a new safety concern is not an absolute number of reports, but rather the evidence of an association that suggests a causal relationship between the drug and an adverse event. In many cases, FDA needs to use multiple data sources rather than relying solely on FAERS.

What is FDA doing to improve drug safety monitoring?

We continue to develop and implement processes needed to support efficient and effective postmarket safety. This includes a postmarket safety modernization initiative and technologies to proactively identify safety issues.

The Sentinel Initiative, through the FDA Sentinel Innovation Center (IC), is testing machine learning and natural language processing technologies to more effectively access and integrate data in clinical narratives for safety studies. Through a series of methodological and infrastructure development projects, FDA has developed capabilities to conduct signal identification analyses in the Sentinel System to complement data from FAERS. The analytic packages and results from these projects are available on the Sentinel Initiative website.

CDER’s Newly Identified Safety Signal process, a postmarket safety initiative, allows for a standardized, interdisciplinary approach to systematically identify, evaluate, and address safety signals. The agency is also implementing natural language processing and machine learning methods to improve review and analysis of FAERS data and is exploring applying these techniques to the medical literature. An example is the Information Visualization Platform (InfoViP), a decision-support software tool that will allow safety reviewers to focus on evaluating complex data and detecting safety concerns.

Finally, FDA continues to ask consumers, health care professionals, and others to help improve the quality of the data we receive by submitting detailed and complete reports of adverse events and medication errors. Complete and detailed reports are immensely helpful to the agency when identifying safety concerns.

Report a serious problem to MedWatch. Complete and submit the report online. Download form or call 1-800-332-1088 to request a reporting form, then complete and return to the address on the pre-addressed form or submit by fax to 1-800-FDA-0178.

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