BACKGROUND Dual therapy with aspirin and clopidogrel increases the risk of gastrointestinal bleeding. Therefore, co-therapy with a proton pump inhibitor (PPI) is recommended by most guidelines. However, there are warnings against combining PPIs with clopidogrel because of their interactions with cytochrome P450 isoenzyme 2C19 (CYP2C19). METHODS The effects of the combined or separate intake o...

background: ischemic heart disease is the leading cause of death in most societies. in a pathophysiologic point of view, it chiefly results from the formation of thrombus in coronary arteries which could not be only prevented by aspirin. many of clinical trials have shown the long-term benefits of antiplatelet drugs in reducing the risk of thrombotic accidents. objectives: clopidogrel is a thie...

CONTEXT Prior mechanistic studies reported that omeprazole decreases the platelet inhibitory effects of clopidogrel, yet the clinical significance of these findings is not clear. OBJECTIVE To assess outcomes of patients taking clopidogrel with or without a proton pump inhibitor (PPI) after hospitalization for acute coronary syndrome (ACS). DESIGN, SETTING, AND PATIENTS Retrospective cohort ...

BACKGROUND Clopidogrel bisulfate is an antiplatelet agent used to prevent ischaemic events in patients with vascular disease. Current guidelines recommend withholding clopidogrel for 7 days pre-operatively. However these are not based on orthopaedic patients. We therefore decided to survey current orthopaedic practice to see whether this complied with available clinical data. METHOD A questio...

BACKGROUND Pretreatment is not the most common strategy practiced for clopidogrel administration in elective coronary stenting. Moreover, limited information is available on the antiplatelet pharmacodynamics of a 300-mg versus a 600-mg clopidogrel loading dose, and the comparative effect of eptifibatide with these regimens is unknown. METHODS AND RESULTS Patients undergoing elective stenting ...

We have investigated the mechanisms by which clopidogrel inactivates human cytochrome P450 2B6 (CYP2B6) in a reconstituted system. It was found that clopidogrel and its thiolactone metabolite, 2-oxo-clopidogrel, both inactivate CYP2B6 in a time- and concentration-dependent manner. On the basis of k(inact)/K(I) ratios, clopidogrel is approximately 5 times more efficient than 2-oxo-clopidogrel in...

UNLABELLED We evaluated the response to clopidogrel among aspirin-resistant versus aspirin-sensitive patients undergoing elective coronary stenting. Patients (n = 150) treated with aspirin but not clopidogrel had blood samples drawn at baseline and 24 h after clopidogrel loading. Depending on the definition used, 9% to 15% were resistant to aspirin and 24% to clopidogrel. About half of the aspi...

PURPOSE Whether addition of cilostazol is superior to increasing dose of clopidogrel in patients with hyporesponsiveness to chronic clopidogrel therapy is unknown. MATERIALS AND METHODS We studied 73 patients with hyporesponsiveness to clopidogrel on standard dual antiplatelet therapy for more than 2 weeks. Clopidogrel hyporesponsiveness was defined as percent inhibition of P2Y12 reaction uni...

BACKGROUND Clopidogrel has been widely used to prevent recurrent ischemia in patients with acute coronary syndrome (ACS). However, inter-individual variability in response to clopidogrel has been a problem in the clinical setting. The aim of the present study was to investigate the frequency of clopidogrel resistance and to determine the clinical, pharmacokinetic, and pharmacogenetic factors fo...