Drug products with the same active chemical ingredients sold under the same generic name but often with different brand names. Generic equivalents are often assumed to be, but are not necessarily, therapeutic equivalents. The term has such inconsistent meaning that it must be used with care or avoided.
A drug sold under its chemical (generic) name when patent and trademark protection for the drug under a proprietary or trade name has expired. Generic equivalents are generally less costly than the trademarked product. In many states, substitution of a generic equivalent by a pharmacist is permitted (or required) unless the physician specifically orders that the trademarked product be dispensed. The physician who specifically describes a trademarked product may feel that the generic drug has some differences not detectable by simple chemical analysis; for example, he may believe that its ability to dissolve may not be as good as the brand name product, or that it is not produced with as good quality control as that of a major drug firm which he trusts. The physician’s reasons for choosing a trademarked product over a generic one are often well-founded.