不同负荷剂量氯吡格雷对血小板聚集率的影响

目的比较两种剂量氯吡格雷的起效时间及安全性,为急性冠状动脉（冠脉）综合征患者用药方案提供依据。方法60例急性冠脉综合征使用不同负荷剂量氯吡格雷患者随机分为A组（300mg）和B组（600mg）,均予氯吡格雷75mg／d后续治疗。以腺苷二磷酸（ADP）5μmol／L及20μmol／L作为诱导剂检测服药前及服药后2h和6h的血小板聚集率,并检测服药前及服药后第3天的血自细胞及血小板计数。结果在ADP20μmoL／L诱导的血小板聚集检测中,两组均显示服药后6h比服药后2h达到更高的血小板聚集抑制水平A组（29．75±12．11）％比（43．63±14．31）％,P〈0．05;B组（28．86±10．24）％比（34．86±10．84）％,P〈0．05]。B组与A组相比,在服药后2h即起到更加明显的血小板聚集抑制作用（34．86±10．84）％比（43．63±14．31）％,P〈0．05]。服药后3d内所有人选患者均无出血、自细胞减少及血小板减少等事件发生。结论氯吡格雷600mg作为负荷剂量较之300mg可以更快地达到较高水平的血小板抑制作用,且两者安全性相似。

The effect of different loading doses of clopidogrel on platelet aggregation

OBJECTIVE: To compare the short-term efficacy and safety of high loading dose (600 mg) clopidogrel treatment with those of routine loading dose (300 mg) in patients with acute coronary syndrome and provide evidence for planning clopidogrel treatment. METHODS: 60 patients were randomized into two groups, One group received 300 mg loading dose clopidogrel, while the other received 600 mg and both were followed by 75 mg daily thereafter. Adenosine diphosphate (ADP) (5 micromol/L and 20 micromol/L) induced platelet aggregation was examined at baseline (before administration), 2 hours and 6 hours after administration and the count of white blood cell and platelet 3 days after loading dose. The primary end points were hemorrhagic events, granulocytopenia and thrombocytopenia within 3 days after administration. RESULTS: With a high-dose agonist (20 micromol/L ADP), loading doses of clopidogrel at 300 mg and 600 mg both produced greater inhibition of baseline ADP (20 micromol/L) induced aggregation 6 hours after administration than 2 hours group of 300 mg: (29.75+/-12.11)% vs (43.63+/-14.31)%, P<0.05. Group of 600 mg: (28.86+/-10.24)% vs (34.86+/-10.84)%, P<0.05]. Treatment with clopidogrel at 600 mg loading dose had a marked earlier effect on platelet aggregation 2 hours after administration than that of 300 mg (34.86+/-10.84)% vs (43.63+/-14.31)%, P<0.05]. The platelet aggregation of the two groups tended towards similar at 6 hours after the procedure (28.86+/-10.24)% vs (29.75+/-12.11)%, P>0.05]. There were no episodes of hemorrhagic events, granulocytopenia and thrombocytopenia within 3 days after the procedure. CONCLUSIONS: In Chinese patients with acute coronary syndrome platelet aggregation can be inhibited more rapidly and more effectively with clopidogrel at 600 mg loading dose when compared with that at 300 mg loading dose and the safety aspect between the two different loading doses is equivalent.