Switching from Clopidogrel to Prasugrel in patients undergoing PCI: A meta-analytic overview

Blood platelet surface receptor genetic variation and risk of thrombotic episodes

Haemostasis is a set of processes whose main task is to prevent blood loss by creating barriers in damaged vessels. Because of the large number of platelet surface receptors and their many agonists, platelets can be activated in normal and pathologic states leading to thromboembolic complications. Although age, blood pressure, LDL and HDL, diabetes, lack of physical activity, obesity and stress are well established risk factors, recent work has shown that platelet receptor polymorphisms also impact platelet function. The most common polymorphisms include 14A/T (PAR-1), 139C/T, 744T/C, 52G/T, i-ins801A (P2Y12), 1622A/G, -5T/C (GPIbα) 1565C/T (GPIIb/IIIa) and 807C/T (GPIa/IIa). This review examines the influence of these polymorphisms on cardiovascular disease including myocardial infarction, deep venous thromboembolism and acute coronary syndromes. Elucidation of these genetic variations will facilitate our understanding of the complex molecular mechanisms involved with physiologic and pathophysiologic platelet activation and clot formation.

The Herb-Drug Interaction of Clopidogrel and Xuesaitong Dispersible Tablet by Modulation of the Pharmacodynamics and Liver Carboxylesterase 1A Metabolism

Objective

Clopidogrel and Xuesaitong dispersible tablet (XST) have been clinically proven to be effective for treating cardiocerebrovascular disease. The present study was to investigate the herb-drug interaction of Clopidogrel and XST by modulation of the pharmacodynamics and liver Carboxylesterase 1A(CES1A) metabolism.

Methods

30 male SD rats were randomly divided into a control group (equal volumes of saline, 6 rats for mRNA analysis), a clopidogrel group (clopidogrel with dose 30 mg/kg), and a combination group (clopidogrel and XST, with dose 30 and 50 mg/kg respectively, each group continuous administration once daily for 30 days). The clopidogrel and combination group comprised 12 rats, with 6 designated for mRNA analysis and 6 for the pharmacokinetic study. The 2-bromo-3'-methoxyacetophenone- (MPB-) derivatized clopidogrel active thiol metabolite (CAMD) was measured by UHPLC-MS/MS for pharmacokinetics (n=6). The expression of CES1A mRNA was examined with real-time RT-PCR (n=6). Molecular simulation was used to investigate the inhibition effect of XST on the CES1A protein. The CAMD pharmacodynamics and CES1A metabolism were investigated to evaluated the herb-drug interaction.

Results

Clopidogrel and XST coadministration appreciably increased the Cmax, AUC, and MRT of CAMD. However, the expression of CES1A mRNA was decreased accordingly. It also indicated that the bioactive components in XST had good interaction with the CES1A metabolism target by molecular simulation. The animal study indicated that clopidogrel and XST coadministration produced significant herb-drug interactions at active CAMD pharmacokinetic and CES1A metabolic enzyme aspect.

Conclusion

30-days dose of coadministration altered hepatic CES1A protein and resulted in reduced plasma levels of active CAMD. both the decreased CES1A mRNA expression and the inhibition on the protein were due to the combination of XST, which accordingly upregulated the pharmacokinetics of plasma active CAMD.