Objective To explore the relationship between ABCB1 and CYP2C19 genotype and efficacy of clopidogrel in patients with acute atherosclerotic cerebral infarction.

Methods Totally, 115 inpatients within 7 days after the onset of acute atherosclerotic cerebral infarction were assigned to three groups according to CYP2C19 genotype:extensive metabolizers, intermediate metabolizers, and poor metabolizers. Then, according to ABCB1 genotype, patients were divided into wild type and mutant type. Moreover, according to the number of gene mutations, patients were grouped into A (absence of variant CYP2C19 and ABCB1), B (either variant CYP2C19 or ABCB1), and C (both variant CYP2C19 and ABCB1). All the patients were treated with conventional treatments in the stroke unit, and thrombelastogram (TEG) was used to test platelet function and platelet inhibition ratio after patients taking clopidogrel for seven days. On admission and after taking clopidogrel for seven days, all the patients were evaluated by neurologic function scales including the National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS).

Results The patients of extensive metabolizers, intermediate metabolizers, and poor metabolizers were 46, 48 (40 *1/*2, 8 *1/*3), and 21 (18 *2/*2, 3 *2/*3), respectively. The patients of wild type and mutant type were 49 and 66. The number of patients of Group A, B, and C was 23, 50, and 42, respectively. Among different genotype of CYP2C19, ABCB1, and number of gene mutations, there were no significant differences in the platelet inhibition ratio, platelet function and neurologic function variety during the acute phase of stroke.

Conclusions In patients with acute atherosclerotic cerebral infarction in our study, the effect of the gene polymorphism of CYP2C19 and ABCB1 on clopidogrel has not been observed.