AUTHOR=Bender Lena , Hirsch Martin , Schulze-Bonhage Andreas TITLE=Increase of Brivaracetam serum concentration with introduction of Cenobamate JOURNAL=Frontiers in Pharmacology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1571376 DOI=10.3389/fphar.2025.1571376 ISSN=1663-9812 ABSTRACT=IntroductionCenobamate is a new antiseizure medication approved for polytherapy of focal epilepsy with complex hepatic metabolism and effects on liver enzymes. So far, data are limited with regard to possible interactions with other antiseizure medications. We here report effects of Cenobamate on serum levels of Brivaracetam, a SV2-agent modulating presynaptic neurotransmitter release.MethodsRetrospective analysis of Brivaracetam serum concentrations with new introduction of Cenobamate with Brivaracetam as a constant baseline antiseizure medication in 19 patients with focal epilepsy. Statistical analysis using paired Fisher´s exact t-Test.ResultsNew introduction of Cenobamate lead to a statistically significant increase in Brivaracetam serum concentrations with a mean increase by 27%. This was infrequently accompanied by adverse effects.DiscussionNew introduction of Cenobamate to a pre-existing antiseizure regimen containing Brivaracetam leads to considerably increases in Brivaracetam, probably related to inhibition of CYP2C19. This needs to be taken into account when interpreting changes in treatment efficacy, but also when relating potential adverse effects to baseline vs. newly introduced treatment.