Jakubowski J A, Stampfer M J, Vaillancourt R, Deykin D
Br J Haematol. 1985 Aug;60(4):635-42. doi: 10.1111/j.1365-2141.1985.tb07467.x.
Enteric coated aspirin (ECA) at doses of 325-1300 mg is an effective alternative to regular aspirin for inhibition of platelet activity while avoiding gastric irritation. The objectives of this study were to determine: (1) the lowest chronic dose of ECA providing effective inhibition of platelet activities, (2) the time course of the inhibition, and (3) the reappearance of platelet cyclo-oxygenase activity. Seven subjects were studied before and after seven daily doses of 40-325 mg ECA. Serum thromboxane (TX) B2 levels indicated that the lowest dose of ECA resulting in greater than 90% inhibition of platelet cyclo-oxygenase was 80 mg/d. Platelet aggregation and ATP release in response to collagen (1 microgram/ml) and arachidonic acid (1 mM) were abolished and bleeding times were prolonged from 6.1 +/- 1.5 min to 9.7 +/- 2.8 min (mean +/- SD, P less than 0.01). Examination of platelet cyclo-oxygenase activity on a daily basis revealed that 24 h after the first 80 mg dose serum TXB2 had decreased by approximately 60% and was suppressed by more than 90% after four doses. Recovery of platelet cyclo-oxygenase activity after a single 80 mg dose of ECA was delayed for 48-72 h indicating that aspirin reached the systemic circulation. We conclude that chronic inhibition of platelet activity may be achieved in a cumulative manner with 80 mg ECA/d.
剂量为325 - 1300毫克的肠溶阿司匹林（ECA）是常规阿司匹林的有效替代品，可抑制血小板活性，同时避免胃部刺激。本研究的目的是确定：（1）有效抑制血小板活性的最低慢性ECA剂量；（2）抑制的时间进程；（3）血小板环氧化酶活性的再现。对7名受试者在每日服用7次40 - 325毫克ECA前后进行了研究。血清血栓素（TX）B2水平表明，导致血小板环氧化酶抑制率大于90%的最低ECA剂量为80毫克/天。对胶原蛋白（1微克/毫升）和花生四烯酸（1毫摩尔）的反应中，血小板聚集和ATP释放被消除，出血时间从6.1±1.5分钟延长至9.7±2.8分钟（平均值±标准差，P<0.01）。每天检测血小板环氧化酶活性发现，首次服用80毫克剂量后24小时，血清TXB2下降了约60%，四次服药后被抑制超过90%。单次服用80毫克ECA后血小板环氧化酶活性的恢复延迟了48 - 72小时，表明阿司匹林进入了体循环。我们得出结论，每天服用80毫克ECA可以累积实现对血小板活性的慢性抑制。
