All About Generics
Another common misconception is that generic medications do not work as well as brand-name medications. People may feel that generic products are less potent or take longer to work. Some people believe that the FDA allows a 45 percent difference between brand-name and generic medications. These misconceptions are fueled by the difference in appearance between brand-name and generic products. Fortunately, these are all misunderstandings.
Most generic products are "bioequivalent" to the brand-name product. This means the generic manufacturer has shown that their product contains the same active ingredient as the brand-name product in the same quantity. They have demonstrated that the same amount of medication is absorbed into the body at the same time as the brand-name product.
They have also shown that the medication remains at the same level in the body for the same amount of time as the brand-name product. The idea is that if a generic drug product meets all of these requirements, then it should produce the same effects as the brand-name product.
Generic products that are bioequivalent to the brand-name product are also called "A-rated." Generic medications that cannot demonstrate bioequivalence are called "B-rated." In most states, the pharmacist can substitute an A-rated generic for the brand-name product, or may be required to by law unless the prescriber or patient specifies otherwise.
The pharmacist cannot substitute a B-rated product for the brand-name product without contacting the prescriber. If you receive a generic product, it is either A-rated or the prescriber has authorized the B-rated product. Your pharmacist can tell you if you are getting an A-rated or B-rated generic medication.
The statistics used to determine bioequivalence are complicated, which is why some people believe that there may be a 45 percent difference between brand-name and generic medications. In reality, a bioequivalent generic product will not differ from the brand-name product any more than two batches of the brand-name product may differ, and most A-rated generic products differ from the brand-name product by less than 4 percent.
To address the difference in appearance that fuels some of these misconceptions, companies that manufacture the brand-name product will certainly obtain a copyright for the appearance of their tablet, for example. In addition, the FDA requires all medications to have a unique appearance for purposes of identification. Therefore, no two medications can or will look alike.
The only exception is when the manufacturer of a brand-name medication also produces a generic version of their drug (called an "authorized" or "branded" generic), in which case the generic form can look identical to the brand-name product.