Genetic variations and response to antiepileptic drug

Despite the state-of-the-art medical treatment with antiepileptic drugs (AED), at least one-third of newly diagnosed epilepsy patients may show poor response to AED. Although the biological mechanism of diverse responses to AED is poorly understood, it is likely that multifactorial factors could be responsible for the different responses. Clinical factors such as etiology of epilepsy and pre-treatment seizure frequency can predict the different responses to AED, whereas the role of genetic variations in individuals contributing to variation in response to AED is still conflicting. The inconsistency in proving the genetic roles in different responses to AED may be partly explained by (1) diversity of the definition of response to AED, (2) heterogeneity of the subjects, and (3) lack of multigenetic approach. While we hypothesize that the genetic variations in individuals may independently contribute to different responses to AED, multigenetic interactions including both the genetic variations of pharmacokinetics and pharmacodynamics may take place.