Purpose of review: This review summarizes the current FDA practice in developing risk- and evidence-based product-specific bioequivalence guidances for antiepileptic drugs (AEDs).
Recent findings: FDA's product-specific guidance (PSG) for AEDs takes into account the therapeutic index of each AED product. Several PSGs for AEDs recommend fully replicated studies and a reference-scaled average bioequivalence (RS-ABE) approach that permit the simultaneous equivalence comparison of the mean and within-subject variability of the test and reference products. The PSGs for AEDs published by FDA reflect the agency's current thinking on the bioequivalence studies and approval standards for generics of AEDs. Bioequivalence between brand and generic AED products demonstrated in controlled studies with epilepsy patients provides strong scientific support for the soundness of FDA bioequivalence standards.
Keywords: AED; Bioequivalence; NTI; PSG.