Hidden Paradoxes in Generic Drug Substitution Affecting Pharmacotherapy

Abstract EN

The issue of the generic versus brand-name drug interchangeability is an intensely debated theme historically focused on whether bioequivalence testing can guarantee therapeutic efficacy.

The controversy is supported by reports of the lack of therapeutic equivalence between some generic medicinal products and brand-name drugs, as well as by a great deal of editorials expressing a negative view on generic drug substitution.

This could be of particular concern for critical therapeutic categories such as psychotropic, cardiovascular, and metabolic/endocrine drugs as well as for special subpopulations such as elderly, debilitated/psychoneurotic patients, infants and children [1, 2].

To deal with this issue, large, prospective controlled evaluations have been proposed, providing information on how current bioequivalence and pharmacological equivalence translate into clinical equivalence [3].

In our opinion, however, although on one hand this strategy could be suitable in clinical trials to ascertain the “essential similarity” requirement in drug substitution—in terms of active ingredient (amount and type), route of administration, and therapeutic effectiveness—on the other hand, it might be insufficient in real practice to support the therapeutic equivalence for the general population.

This could also be due to the possible influence of the marketing to patient’s response.