Pharmacotherapeutics for Advanced Practice A Practical Approach THIRD EDITION

Generic Drugs Versus Brand Name Drugs Substituting a generic drug for a brand name drug is a common practice. In many states, it is required. When the patent on a brand name drug expires, other drug manufacturers can then produce the same drug formula under its generic name (the generic name and formula of a drug are always the same; only the brand names change). This practice not only benefits the manufacturer but decreases the cost to the consumer. To ensure safety, the FDA must grant approval for these drugs, and rigorous testing is again required to ensure that all generic drugs meet specifications for quality, purity, strength, and potency. Generic drugs must demonstrate therapeutic equivalence to the brand name equivalent. They must be manufactured under the same strict standards and meet the same batch requirements for identity, strength, purity, and quality as the brand name drug. Bioavailability can only differ from the brand name by less than 4%. To obtain FDA approval, the generic drug is administered in a single dose to at least 18 healthy human subjects. Next, peak serum concentration and the area under the plasma concentration curve (AUC) are measured. The values obtained for the generic drug must be within 80% to 125% of those obtained for the brand name drug. Most generic drugs have a mean AUC within 3% of the brand name drug. There has been no reported therapeutic difference of a serious nature between brand name products and FDA-approved generic products. For more information, see Table 1.1, which presents FDA equivalency ratings for brand name and generic drugs.