Retrospective Study of the Serum Level of Levetiracetam in Focal Epilepsy Related to Seizure Frequency and Side Effects in a Single Center: A Preliminary Study

Abstract

Antiepileptic drugs (AEDs) are the basic treatment for epilepsy, and more than 20 kinds of drugs have been developed. Despite recent efforts for new drug discovery, approximately 30% of epilepsy patients suffer from drug-resistant, intractable seizures, even with multiple uses of AEDs. Other treatments, including surgical resection, ketogenic diet, and vagus nerve stimulation, Antiepileptic drugs (AEDs) are the basic treatment for epilepsy. Levetiracetam is known to affect the synaptic vesicle protein Sv2A, and its therapeutic range has been determined by experimental data and the literature. Considering the variability in clinical situations of each patient, or center-dependent, affecting seizure-free rate or adverse drug reactions, the subdivided therapeutic range of levetiracetam in epilepsy patients in a single center and their clinical characteristics were retrospectively analyzed in this study. Data were collected and retrospectively reviewed for patients who were diagnosed with epilepsy and visited the neurology outpatient center or were admitted to the Seoul National University Hospital from January 19, 2016 (when laboratory results for the concentration of levetiracetam began) to December 31, 2020. In this study, seizure freedom was achieved in >60% of all three groups with levetiracetam. Seizure-free rates tended to be higher with increasing levetiracetam concentrations; however, the statistical significance was not clear. The frequency of adverse drug reactions tended to be higher in the moderateand high-dose groups than in the low-dose group, although this difference was not statistically significant. Further studies with multiple factors and situations with a larger number of patients will guarantee the detailed implications of levetiracetam concentration related to drug efficacy and adverse drug reactions in real clinical situations.