New Anticonvulsants: Interchangeability Issues and the Use of Generic Anticonvulsants in Clinical Practice

This article looks into interchangeability and therapeutic equivalence of innovator and generic anticonvulsants — the first-generation and new antiepileptic drugs (AEDs). The results of a number of clinical trials assessing therapeutic equivalence of generic AEDs support the opinion that these medicines could only be substituted provided an ultra-cautious approach is used, even if the case involves only one International Nonproprietary Name, including, but not limited to different dosage forms of one and the same product. The aim of the study was to analyse factors leading to incorrect assessment of therapeutic equivalence of new and generic anticonvulsant drugs, and to improve methodological approaches to conducting clinical trials of these products. The paper cites data from Russian and foreign sources which state that the substitution of AEDs in some patients in full remission may result in adverse reactions or relapse of seizures. The analysis of the experience of scientific, expert, and regulatory institutions made it possible to develop a course of actions to be used when substituting AEDs and conducting clinical trials that assess therapeutic equivalence of new and generic anticonvulsants. The proposed methodology will help minimise potential health risks brought about by various factors that result in incorrect assessment of AEDs therapeutic equivalence and interchangeability.