Equivalence of Generic Drugs : Part 3

by Food and Drug Administration (FDA)

(Page 3 of 3)

A staff of nearly 50 chemistry reviewers in the generics office sifts through stacks of data submitted by a firm after it has conducted extensive product testing. The applications are reviewed for their scientific content and for such manufacturing procedures as validation methods, raw material specifications, and container and closure systems.

Eight pharmacists review generic labeling. Part of their mission is to anticipate problems of confused or mistaken identity that can arise in drug labeling. In some cases, the pharmacists reject a product's trade name if it is too similar to another product's.

Kent Johnson, the generics office's associate director of labeling and professional support, said that having clearly distinct names is especially important to avoid drug mix-ups in ambulatory-care facilities, institutional settings, and in emergency rooms because there may not be enough time for the staff to closely examine the label.

Pioneer drugs are often protected by several patented indications in their labeling. Labeling for generic products reflects only approved indications that are not patent protected. Generics office pharmacists monitor the labeling and review new labeling as exclusive claims expire and are added to generic labels.

FDA's stepped-up effort to improve and monitor generic drug production, coupled with the industry's revitalized energy, should continue to provide consumers with safe, effective and affordable drugs.

Drug Terms

Pioneer: The first version of a drug, which is marketed under a brand name. For example, Valium is the brand name for the first marketed version of the anti-anxiety drug diazepam. Generic: A version of a drug that is equivalent to the pioneer or brand-name drug and is not marketed until the pioneer drug's patent exclusivity has expired. These "copies" are often marketed under just the generic name of the drug — for example, Diazepam.

What Is Bioequivalency?

Generics are not required to replicate the extensive clinical trials that have already been used in the development of the original, brand-name drug. Instead, they must show they are bioequivalent to the pioneer drug and fall into acceptable parameters set for bioavailability, which is the extent and the rate at which the body absorbs the drug.

Scientists measure the time it takes the generic drug to reach the bloodstream. This gives them the rate of absorption (or bioavailability) of the generic drug, which they then compare to that of the pioneer drug. The generic version must deliver the same amount of active ingredients into a patient's bloodstream and in the same time as the pioneer drug. Brand-name drugs are subject to the same bioequivalency tests as generics when their manufacturers reformulate them.

When Getting Your Prescription Filled ...

Before leaving your doctor's office and getting a prescription filled, there are some points to remember and things to consider. First, FDA has taken decisive regulatory action against companies found to be producing inferior products — both brand-name and generic products. And the agency will continue to ensure the safety and effectiveness of drugs on the market.

Second, physicians and their patients should discuss and decide whether a brand-name or generic is the best therapy. There should be an agreement between them, and a physician should be aware of which drug a patient is taking. If they jointly decide to change a therapy — whether it be a switch between two brand-name products or between brand-name and generic — they should both commit to follow carefully the outcome of that change in therapy.

Third, pharmacists and health-care providers should give careful attention to FDA evaluations of therapeutic equivalence. A drug's therapeutic rating is published monthly in the "Orange Book," Approved Drug Products With Therapeutic Equivalence Evaluations. The rating will indicate whether a drug has been judged by the agency to be therapeutically equivalent by meeting the criteria of pharmaceutical equivalents, bioequivalence, labeling, and good manufacturing practices.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.