Valproic Acid-Induced Thrombocytopenia in Treatment-Resistant GABRB3 Genetic Epilepsy: A Case Report

Valproic acid (VPA) is utilized in the management of a variety of seizure and mood disorders. A rare side effect of this medication is dose-dependent thrombocytopenia. In this case, we report a patient with a treatment-resistant epilepsy GABRB3 genetic variant phenotype who was admitted for sepsis and found to have significant thrombocytopenia with clinical manifestations of epistaxis and easy bruising, which was found to be due to VPA use rather than secondary to other clinical pathologies. The patient's clinical condition improved with supportive treatment including fluid rehydration. Platelet counts normalized after a transfusion and holding of her valproate. She experienced breakthrough seizures despite the initiation of diazepam. The decision was made to restart VPA per Neurology consult recommendations for better seizure control. She had no breakthrough seizures reported after restarting VPA in the hospital. This case highlights the importance of monitoring antiseizure medication side effects, especially in populations at higher risk due to treatment resistance.