There are economic and clinical incentives for both patients and physicians to preferentiallyutilize generic medications when available, since switching to generic prescription drugs canreduce total prescription medication expenditures due to their substantially lower costs. TheCongressional Budget Office estimates that generic substitution under Medicare Part D reducedtotal prescription drug costs for Medicare beneficiaries in 2007 by $33 billion, 55% lower than ifno generic substitution had occurred. The Abbreviated New Drug Application (ANDA) usuallyincludes in vivo plasma bioequivalence studies to demonstrate therapeutic equivalence of testproduct to the reference product. This method has been time-tested, through retrospectivestudies and in clinical practice, as an effective method to ensure comparable safety and efficacyof the test product. However, there are situations where in vivo plasma bioequivalence studiesmay not be the appropriate route to generic approval. The need to provide access to new, safeand effective generic drugs for patients is therefore met with controversial innovative evaluationmethods. It is important for the FDA to monitor the post-approval drug safety, effectiveness,usage, and substitution patterns of these generic drugs. We propose the following specificaims: 1) Assess clinical outcomes with brand and generic drugs by conducting a systematicevaluation of clinical trials and observational studies; 2) Estimate generic and brand medicationutilization and switchback rates and medical service utilization associated with generic switchingusing Medicare claim databases to assess individual level use of a brand product and itsgenerics; and 3) Determine if controversy around a generic drug approval impacted perceptionsof the generic drug quality by conducting a national survey of patient and physician experiencesabout the model brand and generic drug product use. Findings will have significant clinical andpolicy impacts on current and future generic drug use in the United States, as the study willinform the agency on the development of methods to assess the safety and effectiveness ofgeneric drugs in the marketplace, especially when a controversy exists in the generic approvalprocess. The proposed study is innovative with its proactive, mixed-methods approaches, anduse of social media such as Facebook and online physician forums to conduct surveys. Theexpected outcomes of this study are new decision science and strategies for the Office ofGeneric Drugs on methods to assess the safety and effectiveness of generic drugs in themarketplace, especially when novel bioequivalence methodology has been used in the genericapproval process.

Public Health Relevance

With increasing demand for safe and effective generic drug products; it is imperative that thepublic have confidence in the generic products on the market. For most generic drugs; theFDA's approval requirements are sufficient to assure safety and efficacy. But increasingavailability of complex generic products has led to controversy surrounding the approvalprocess. The purpose of this collaborative agreement is to develop strategies to monitor andassure safety and effectiveness of generic drugs after they are marketed.

National Institute of Health (NIH)
Food and Drug Administration (FDA)
Research Project--Cooperative Agreements (U01)
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Special Emphasis Panel (ZFD1-SRC (99))
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Impaq International, LLC
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