Background: Several studies have shown that patients with diabetes mellitus (DM) exhibit an impaired response to clopidogrel. This may contribute to their increased risk of recurrent atherothrombotic events, despite the use of dual-antiplatelet therapy. The mechanisms for impaired clopidogrel response in DM patients have not been fully elucidated.
View Article and Find Full Text PDFObjectives: The purpose of this study was to assess the in vitro P2Y12 receptor inhibitory effects of cangrelor on platelets from patients on maintenance prasugrel therapy treated with 2 reloading dose regimens.
Background: Despite its more potent and rapid antiplatelet effects compared with clopidogrel, recent studies have shown variability in prasugrel-mediated P2Y12 receptor inhibition, particularly in high-risk settings. Cangrelor is a potent intravenous P2Y12 receptor inhibitor.
Smokers have a greater relative benefit of clopidogrel therapy compared with nonsmokers, likely attributed to its enhanced pharmacodynamic (PD) effects. However, to date, all PD studies have been conducted in patients on dual antiplatelet therapy with aspirin and clopidogrel, and it is unknown whether clopidogrel monotherapy can offer more effective antithrombotic effects compared with aspirin alone among smoking patients. Sixty aspirin-treated (81 mg/day) patients with vascular disease, classified as nonsmokers, light smokers, and heavy smokers according to cotinine serum levels, were enrolled.
View Article and Find Full Text PDFSmoking enhances the P2Y12 receptor inhibitory effects of clopidogrel. Nicotine increases P2Y12 receptor expression in platelet lysates from healthy volunteers. However, the impact of cigarette smoking on platelet P2Y12 receptor binding in clopidogrel-treated patients with coronary artery disease (CAD) is unknown.
View Article and Find Full Text PDFIncreased body weight is independently associated with impaired clopidogrel pharmacodynamic (PD) response. Prasugrel has more potent PD effects compared with clopidogrel, although its PD effects in obese patients are unknown. The aim of this prospective, randomised, study was to compare the PD effects of standard-dose prasugrel [60 mg loading dose (LD)/10 mg daily maintenance dose (MD)] with high-dose clopidogrel (900 mg LD/150 mg daily MD) in non-diabetic obese [body mass index (BMI) ≥30 kg/m²] patients, with coronary artery disease (CAD) on aspirin therapy.
View Article and Find Full Text PDFJ Thromb Thrombolysis
April 2014
J Thromb Thrombolysis
October 2014
Patients with diabetes mellitus (DM) have increased propensity to generate thromboxane A2 (TXA2) and other eicosanoids which can contribute to their heightened platelet reactivity. EV-077 is a potent thromboxane receptor antagonist and thromboxane synthase inhibitor and thus represents an attractive therapy in patients with DM. However, the effects of EV-077 on pharmacodynamic (PD) profiles in patients with DM and coronary artery disease (CAD) while on antiplatelet therapy is poorly explored and represented the aim of this in vitro pilot investigation.
View Article and Find Full Text PDFDifferent aspirin dosing regimens have been suggested to impact outcomes when used in combination with adenosine diphosphate (ADP) P2Y12 receptor antagonists. Prior investigations have shown that not only aspirin, but also potent ADP P2Y12 receptor blockade can inhibit thromboxane A2-mediated platelet activation. The impact of aspirin dosing on ADP mediated platelet activities is unknown and represents the aim of this in vitro pilot pharmacodynamic (PD) investigation.
View Article and Find Full Text PDFPlatelets from patients with diabetes mellitus (DM) are hyper-reactive and whether cangrelor, a potent intravenous P2Y(12) receptor blocker, has differential pharmacodynamic (PD) effects according DM status is unknown. The aim of this investigation was to evaluate the in vitro PD effects of cangrelor in coronary artery disease (CAD) patients with and without DM. This prospective study enrolled 120 clopidogrel-naïve patients with CAD on aspirin therapy.
View Article and Find Full Text PDFDiabetes mellitus (DM) is the most important predictor of chronic kidney disease (CKD), and pharmacodynamic (PD) studies have shown that DM patients with impaired renal function are characterized by reduced clopidogrel response. However, post-hoc PD studies conducted in unselected cohorts, composed of both DM and non-DM patients, have reached controversial findings on the effects of CKD on clopidogrel response, likely attributed to patient heterogeneity. The impact of renal function on clopidogrel response in non-DM patients remains unexplored and represented the aim of this prospective investigation.
View Article and Find Full Text PDFPatients with type 2 diabetes mellitus (T2DM) have impaired clopidogrel-induced antiplatelet effects, which may be in part attributed to their reduced sensitivity to insulin and consequently, results in upregulation of the P2Y12 signalling pathway. It has been hypothesised that insulin sensitising strategies may enhance clopidogrel-mediated P2Y12 inhibitory effects. The aim of this pilot pharmacodynamics (PD) study was to assess the impact of pioglitazone on clopidogrel-mediated P2Y12 inhibitory effects in patients with T2DM.
View Article and Find Full Text PDFObjectives: The purpose of this study is to assess the pharmacodynamic effects of different prasugrel dosing regimens in patients on maintenance prasugrel therapy.
Background: There are a growing number of patients on chronic prasugrel therapy regimens, leading to questions about the dosing regimen of prasugrel to administer if percutaneous coronary intervention is required.
Methods: This is a prospective pharmacodynamic study in patients (n = 64) receiving maintenance prasugrel therapy who were randomly allocated to a 10 mg, 30 mg, or 60 mg dose of prasugrel.
Objectives: This study sought to assess the presence of a dose-response effect of cigarette smoking and its impact on high on-treatment platelet reactivity (HPR) in patients with diabetes mellitus treated with clopidogrel.
Background: Cigarette smoking is an inducer of cytochrome P450 1A2, a hepatic enzyme involved in clopidogrel metabolism. If cigarette smoking is associated with a dose-response effect on pharmacodynamic measures in clopidogrel-treated patients is unknown.
Catheter Cardiovasc Interv
January 2013
Background: In patients on dual antiplatelet therapy with aspirin and clopidogrel, the adjunctive use of cilostazol is associated with enhanced platelet inhibition. However, if cilostazol exerts different pharmacodynamic (PD) effects according to levels of on-treatment platelet reactivity remains unknown. This study aimed to determine the PD effects of cilostazol in patients with and without high on-clopidogrel platelet reactivity (HPR) according to diabetes mellitus (DM) status.
View Article and Find Full Text PDFBackground: Low-dose aspirin (LDA) and nonsteroidal anti-inflammatory drugs (NSAIDs) are often used concomitantly; however, some NSAIDs may interfere with LDA antiplatelet activity.
Objective: We evaluated the impact of coadministered enteric-coated naproxen 500 mg and immediate-release esomeprazole magnesium 20 mg (fixed-dose combination) on LDA-mediated platelet cyclooxygenase (COX)-1 inhibition.
Methods: In this Phase I, single-center, double-blind, placebo-controlled study, healthy volunteers (50-75 years) received enteric-coated LDA 81 mg once daily (QD) on days 1 to 5 (open-label), then enteric-coated LDA 81 mg QD plus either naproxen/esomeprazole magnesium or placebo twice daily (BID) on days 6 to 10 (randomized).
J Am Coll Cardiol
September 2011
JACC Cardiovasc Interv
August 2011
Objectives: The aim of this study was to evaluate the impact of the phosphodiesterase (PDE) inhibitor pentoxifylline on platelet function profiles in patients receiving dual antiplatelet therapy (DAPT).
Background: Previous studies have shown that, in patients receiving DAPT, the adjunctive use of a PDE inhibitor enhances platelet inhibition, particularly in those presenting with diabetes mellitus (DM). However, the pharmacodynamic (PD) effects of the PDE inhibitor pentoxifylline on platelet function profiles in DM patients receiving DAPT are unknown.
Patients with end-stage renal disease (ESRD) have abnormalities in the cellular and plasmatic systems regulating blood homeostasis, which may contribute to their risk for thrombotic and bleeding complications. However, their relative contributions in this population are poorly understood. The aim of this study was to evaluate the distribution of enzymatic and cellular abnormalities in ESRD patients on haemodialysis as assessed by thromboelastography (TEG®).
View Article and Find Full Text PDFCilostazol is a platelet inhibitor which when added to aspirin and clopidogrel has shown to reduce the risk of recurrent ischaemic events without an increase in bleeding. These clinical benefits have shown to be more pronounced in patients with diabetes mellitus (DM). However, it remains unknown whether cilostazol exerts different pharmacodynamic effects in patients with and without DM.
View Article and Find Full Text PDFBackground: Safety concerns have recently emerged based on a drug interaction between clopidogrel and proton pump inhibitors leading to reduced pharmacodynamic effects. However, whether such drug interaction is a class effect or a drug effect and if this can be modulated by timing of drug administration remains a matter of debate. The aim of this study was to assess the impact of high-dose pantoprazole therapy, a proton pump inhibitor with low potential to interfere with clopidogrel metabolism, administered concomitantly or staggered, on clopidogrel-mediated pharmacodynamic effects.
View Article and Find Full Text PDFBackground: Patients with type 2 diabetes mellitus (T2DM) have reduced aspirin-induced pharmacodynamic effects. This may be attributed to increased platelet turnover rates resulting in an increased proportion of non-aspirin-inhibited platelets during the daily dosing interval. The hypothesis of this study was that an increase in the frequency of drug administration [twice daily (bid) versus once daily (od)] may provide more effective platelet inhibition in T2DM patients.
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