Epilepsy is one of the most common CNS disorders occurring in approximately 1% of the world population. It is characterized by the occurrence of recurrent attacks of varying symptomatology. It is estimated that 30% of patients, despite the appropriate antiepileptic treatment, still experiencing seizures. In this case we are dealing with so-called the phenomenon of drug resistance. In Poland, this problem concerns about 100–120 thousand patients. Predisposing factors for epilepsy include: onset of symptoms before 1 year of age, high frequency of seizures before treatment and structural changes of the brain, including cortical malformations. Uncontrolled seizures affect the patients quality of life, increasing the risk of injury, affecting the physical well-being and psychosocial functioning.Despite knowing these presumable risk factors for epilepsy, it remains unknown why in the two patients with the same type of epilepsy or the same type of seizure, efficacy of antiepileptic drugs can be extremely different. Potential reasons for this may be genetic factors, changing the pharmacodynamic and pharmacokinetic attributes of antiepileptic drugs. Among these factors is mentioned genetically determined polymorphism of some microsomal enzymes (CYP2C9, CYP2C19), P-glycoprotein, a protein MRP (multidrug resistance-associated protein) and pharmacodynamic malfunction of GABA (GABAA) and ion channels. It seems that research on the mechanisms of drug resistance may lead to the introduction of new therapeutic strategies This article aims to show the impact of genetic factors to the lack of treatment efficacy in epilepsy.

pharmacogenetics, drug-resistant epilepsy, cytochrome P450, drug transporter proteins, single nucleotide polymorphism – SNP