Generic - equivalent drugs use in internal and general medicine patients: distrust, confusion, lack of certainties or of knowledge? Part 3. Clinical issues

Abstract

There are several clinical areas or types of drugs that make prescribing branded drugs preferable, because of potential therapeutic inequivalence or confusion. Bioequivalence criteria may be fine for most drugs, but some conditions may require drug levels with modified variations, like in the case of narrow therapeutic index and critical dose drugs, highly variable drugs and modified-release formulations. Moreover, substitution with generics can be problematic in some patient subpopulations, such as elderly frail people, immunocompromised and transplant patients and patients with epilepsy. We include a list of branded drugs that are considered safer, more effective or with a lower risk of error. The therapeutic substitution is markedly different from therapeutic interchange. The replacement of a brand product with an equivalent has to occur under the control of the physician. At some point in their interaction with individual patients, physicians should let them know that generics are available as substitutes for the more expensive brand-name medications and are equivalent in terms of efficacy and safety. Finally, we hope that a tool like the American Orange book will be also implemented in Italy: it would serve as an accurate reference, that can be useful both to physicians for prescription appropriateness and to patients for their own informed consent.

Keywords

• generic/equivalent drugs, clinical issues, narrow therapeutic index and critical dose drugs, highly variable drugs, special subpopulations, therapeutic substitution and therapeutic interchange.