细胞色素P4503A酶(Cytochrome P450 3A enzymes)在外源性化合物尤其是药物代谢中起重要作用,临床中约有50%的药物经由CYP3A代谢,其中包括多种抗癫痫药物.本文概述了CYP3A的基因家系的结构、分布和调控表达的异同,CYP3A与难治性癫痫患者药物难治性的可能机制———多药耐药基因和P-糖蛋白的关系,CYP3A4基因表达上的差别与药物作用强度和持续时间、急性毒性的相关性. Cytochrome P450 3A enzymes play an important role in exogenous compounds, especially in drug metabolism, and about 50% of the drugs are metabolized by CYP3A in clinic, including a variety of antiepileptic drugs.This article summarizes the CYP3A gene family The relationship between CYP3A and drug refractory to refractory epilepsy --- the relationship between multidrug resistance gene and P-glycoprotein, the difference of CYP3A4 gene expression and the intensity of drug action And the duration, the acute toxicity of relevance.