Abstract: To observe expression of MDR1 mRNA in peripheral blood and the tolerance of flunarizine. MethodsExpression of MDR1 in the peripheral blood of 86 subjects was determined by PTPCR. All subjects were divided into the refractory epilepsy (n=64) group and the control (n=22) group, and the refractory epilepsy group was subdivided into the flunarizine treatment (n=36) group and the placebo treatment (n=28) group. MDR1 mRNA expression was reexamined with the same method. ResultsExpression level of MDR1 mRNA was elevated in the refractory epilepsy group compared with the control group (P＜0.01). After treatment with flunarizine for 7 to 8 weeks, 20 of 36 (55.56%) patients had good effects, but only 1 patient in the placebo group (3.57%) had an effect. Expression of MDR1 mRNA was decreased in the flunarizine group but increased in the placebo group compared with the control group, also it was decreased in the flunarizine group and increased in the placebo group after treatments compared with the beginning of the experiments. Adverse effective rate was 8.33％. ConclusionExpression of MDR1 mRNA in peripheral blood is parallel to that in the brain, so it can be used to evaluate the sensibility of patients to drugs. Flunarizine is effective on refractory epilepsy with overexpression of MDR1 as an addon therapy.

Key words: Epilepsy, Clinical protocols, Genes,MDR, Flunarizine