The Evaluation of Serum Lamotrigine and Ethosuximide Levels and Their Effects on Seizure Frequency in Children with Absence Epilepsy

Abstract

Childhood absence epilepsy is one of the pediatric epilepsy syndromes that include seizures that cause a sudden loss of consciousness. Although the prognosis is usually good, the frequency of such seizures, even up to a hundred times a day, can greatly interfere with a child's learning and attention abilities, leading to poor psychological and cognitive outcomes. Currently, ethosuximide and lamotrigine are usually among the drugs of choice for children with this type of epilepsy syndrome, however, the relationship of blood levels of these drugs with a reduction in seizure frequency has not been studied in general. This study aimed to investigate the serum levels of lamotrigine and ethosuximide and their effect on the seizure rate in children with absence epilepsy. Methods: In this clinical trial study, among children under 15 years of age with absence epilepsy, 60 cases were selected as available and entered into the study, and they were divided into two groups of 30 people, ethosuximide and lamotrigine. Then, each group of mentioned drugs was prescribed separately for four months. The rate of response to treatment was calculated and recorded as a decrease in seizure frequency at the end of the administration period compared to before the administration. Serum levels of drugs at the end of the administration period were evaluated by high-performance chromatography. Results: In this study, the blood levels of both drugs in most children were at the effective therapeutic levels. The comparison of the percentage of children with low, therapeutically effective, and higher serum levels also showed that the number of children with effective drug levels in the ethosuximide group was more than that of the lamotrigine group, however the difference was not statistically significant. The treatment response in the ethosuximide group was 76.7%, which was higher than the lamotrigine group (63.3%), but it was not statistically different.