Effect of Enteric Coating on Antiplatelet Activity of Low-Dose Aspirin in Healthy Volunteers

Author:

Cox Dermot1,Maree Andrew O.1,Dooley Michelle1,Conroy Ronán1,Byrne Michael F.1,Fitzgerald Desmond J.1

Affiliation:

1. From the Department of Clinical Pharmacology (D.C., A.O.M., M.D., M.F.B., D.J.F.), Royal College of Surgeons, Dublin, Ireland; the School of Pharmacy (D.C.), Royal College of Surgeons, Dublin, Ireland; and the Department of Epidemiology (R.C.), Royal College of Surgeons, Dublin, Ireland.

Abstract

Background and Purpose— Aspirin resistance may be relatively common and associated with adverse outcome. Meta-analysis has clearly shown that 75 mg plain aspirin is the lowest effective dose; however, it is not known whether the recent increased use of enteric-coated aspirin could account for aspirin resistance. This study was designed to determine whether enteric-coated aspirin is as effective as plain aspirin in healthy volunteers. Methods— Seventy-one healthy volunteers were enrolled in 3 separate bioequivalence studies. Using a crossover design, each volunteer took 2 different aspirin preparations. Five aspirin preparations were evaluated, 3 different enteric-coated 75-mg aspirins, dispersible aspirin 75 mg and asasantin (25-mg standard release aspirin plus 200-mg modified-release dipyridamole given twice daily). Serum thromboxane (TX) B 2 levels and arachidonic acid–induced platelet aggregation were measured before and after 14 days of treatment. Results— All other aspirin preparations tested were inferior to dispersible aspirin ( P <0.001) in their effect on serum TXB 2 level. Treatment failure (<95% inhibition serum TXB 2 formation) occurred in 14 subjects, none of whom were taking dispersible aspirin. Mean weight for those demonstrating treatment failure was greater than those with complete TXB 2 (>99%) inhibition ( P <0.001). Using logistic regression analysis an 80-kg subject had a 20% probability of treatment failure. Asasantin was the most potent preparation in terms of inhibition of platelet aggregation. Conclusions— Equivalent doses of the enteric-coated aspirin were not as effective as plain aspirin. Lower bioavailability of these preparations and poor absorption from the higher pH environment of the small intestine may result in inadequate platelet inhibition, particularly in heavier subjects.

Publisher

Ovid Technologies (Wolters Kluwer Health)

Subject

Advanced and Specialized Nursing,Cardiology and Cardiovascular Medicine,Neurology (clinical)

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3