Effect of Dividing Low Dose Aspirin on Platelet Reactivity and the Correlation with Patient-related Factors.

Aims: The optimal dosing regimen of aspirin for primary and secondary prevention of ischemic events is a topic of debate. Therefore, the aim of this study is to evaluate whether administering 100 mg aspirin in two divided dose, rather than a single daily dose, is associated with a greater degree of inhibition of platelet aggregation. Methods :Forty-eight patients compliant to once daily 100 mg of aspirin were recruited into this interventional before-after study. Patients were instructed to split the 100 mg aspirin tablet into two halves using a pill splitter and then to administer half tablet of aspirin twice daily for a duration of one to three months. Assessment of platelet aggregation was performed using Multiplate analyzer system with arachidonic acid as an agonist. Furthermore, assessment of the factors associated with platelet aggregation response was also conducted. Results :There was no statistically significant difference in platelet aggregation parameters- including the area under the aggregation curve AUC- between once daily 100 mg and twice daily 50 mg aspirin regimens (20.3 ±11.3 vs. 20.7±15.6, p-value 0.626).There was no significant correlation between the AUC of both dosing regimens and many patients-related factors. Conclusion :The administration of 50 mg twice daily aspirin regimen was not associated with a greater degree of platelets inhibition compared to the once daily 100 mg regimen. [ABSTRACT FROM AUTHOR]