The optimized use of antiepileptic drugs to treatment of epilepsy is usually compromised by lack of therapeutic response, unexpected side effects and unexplained variations of antiepileptics plasma levels. The presence of DNA polymorphism in these persons is associated to alterations on drug transportation, cerebral drug receptors, drug metabolization or severe idiosyncratic side-effects, which could explain some of these problems. Most of antiepileptics are metabolized by cytochrome P450 or UDP-glucoronosyl-transferase. The cytochrome P450 enzymes more clinically significant are CYP1A2, CYP2D6, CYP2C9, CYP2C19 and CYP3A4. Phenytoin is metabolized by CYP2C9 e CYP2C19, and polymorphism reduce metabolic activity to 27-54%, occurring at 20-30% of population, according to the person ethnic origin. The use of pharmacogenetics in the treatment of person with epilepsy has a large potential, but more studies are necessary.
Pharmacogenetic; antiepileptics; epilepsy; cytochrome P450; polymorphisms
