RESUMO
Historically, the most common intervention performed by physicians has been the writing of a prescription. Often the prescription was a combination of active agents and an inactive base. This art is no longer practiced in the United States. Currently, most prescriptions are written for specific "drugs." As the prescription is being written, the physician must decide to administer a brand-name or a generic equivalent. Generics are a class of medications prescribed for reasons of economy, and the physician and the patient expect that the therapeutic effect will be exactly the same as for the brand-name. Bioequivalence of specific agents can be assessed using the FDA's Orange Book. In addition to bioequivalence, many other scientific, ethical, and economic issues should be considered before a decision is made. Prescribing vigilance is necessary, because in many instances available information is often controlling or insufficient to support rational decisions. Brand-names, rather than generics, should be selected when the therapeutic index is narrow or if the likelihood of generic switching is high. The paper will discuss all aspects of the subject.