Ertapenem-Induced Reduction in Valproate Levels: Case Report and Review of the Literature

Abstract

Increasing the dose of valproatemay not compensate for the reduction, which puts the patientat risk for recurrent seizures. Therefore, close monitoring of valproate levels is necessary when initiating a carbapenemantibiotic in patients whose condition has been stabilized withvalproate therapy. Several case reports of significant reductions in serum valproate concentrations following initiation of carbapenemantibiotics have been published. To the authors’ knowledge,however, there has been no published systematic review of thecarbapenem–valproate interaction. We report a case of ertapenem-induced reduction in valproate concentration anddescribe the extent, clinical relevance, potential mechanisms,and therapeutic options for management of the carbapenem –valproate interaction.