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Antiplatelet Drugs (antiplatelet + drug)
Terms modified by Antiplatelet Drugs Selected AbstractsTriflusal: An Antiplatelet Drug with a Neuroprotective Effect?CARDIOVASCULAR THERAPEUTICS, Issue 1 2006José Antonio González-Correa ABSTRACT Triflusal is a derivative of salicylic acid with a well-established platelet aggregation inhibitory profile. Its pharmacokinetic and pharmacodynamic properties differ, however, somewhat from those of acetylsalicylic acid. A number of recent experimental and clinical studies have shown that triflusal is a potentially useful choice in the treatment and prophylaxis of brain ischemia because of its antithrombogenic as well as neuroprotective effects. Its antithrombogenic effect has been demonstrated at the clinical as well as at the experimental level, while its neuroprotective effect has been shown only in experimental models. The drug interferes with thrombogenesis by inhibiting thromboxane synthesis and increasing the levels of cAMP and nitric oxide. Its neuroprotective action is the result of its antioxidant and antiinflammatory effects in brain tissue. From a clinical standpoint triflusal is similar in efficacy to acetylsalicylic acid in preventing stroke, but has less adverse effects, especially it is less likely to cause bleeding. Because of its pharmacodynamic properties and lower rate of adverse reactions, triflusal may be a useful alternative to acetylsalicylic acid in the prevention of stroke. [source] Antiplatelet ,resistance' and ,non-responders': what do these terms really mean?FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 1 2009Victor L. Serebruany Abstract The term ,resistance' should be restricted to very specialized physiologic circumstances, if not abandoned altogether. The term ,non-responder' needs to be placed in the context of the question: ,Non-responder to what?' Even if we would somehow magically know what an optimal response to antiplatelet therapy was, it will still be challenging to demonstrate an ,inadequate' response to antiplatelet therapy. At present there are two alternatives , give more drug or give additional drugs. Both strategies may work in further inhibiting platelet function, but both strategies can also be associated with an increased risk of bleeding. The trick, for the future, much as with our antihypertensive and lipid-lowering armamentaria, will be to know in whom to do what with which drug, and why. Single isolated measurements are not useful , if you don't know where you started, how we would know that antiplatelet drug is producing an ,adequate' clinical effect? There is no evidence of any sort of absolute ,threshold' that must be exceeded for treatment to be effective, and in the absence of this, if we are to evaluate the effect of a given drug, we have to have baseline values (off drug), therapeutic values (on drug), and some sort of assessment of both resting (unstimulated) and agonist-provoked (stimulated) platelet function. Moreover, given all of the different things that platelets do, the ideal assessment of platelet function and drug responsiveness will need to incorporate more than one agonist and some sort of assessment of both platelet activation and platelet aggregation. No one man (or test) tells us everything; it is the totality of the information that gives us the most complete picture. And, ultimately, we need to more firmly establish how the variability in platelet function and drug-associated changes in that function correlates with long-term, hard-endpoint clinical events. [source] Regular or "Super-Aspirins"?JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2001A Review of Thienopyridines or Aspirin to Prevent Stroke PURPOSE: To review the evidence for the effectiveness and safety of the thienopyridines (ticlopidine and clopidogrel) compared with aspirin for the prevention of vascular events among patients at high risk of vascular disease. BACKGROUND: Atherosclerosis and resultant cardiovascular disease are important causes of morbidity and mortality in older people. In particular, atherosclerosis of the cerebral arteries can lead to transient ischemic attacks (TIAs) and stroke. Stroke ranks as the third-leading cause of death in the United States and in 1997 was responsible for over 150,000 fatalities.1 In addition to the mortality associated with this disease, stroke is also a leading source of long-term disability in survivors. Nearly 4.5 million stroke survivors are alive today,1 highlighting the fact that primary, but also secondary, prevention are extremely important for minimizing the complications of this illness. DATA SOURCES: Specialized trial registers of the Cochrane Stroke Group and the Antithrombotic Trialist's Collaboration, MEDLINE, and Embase were searched. Additional unpublished information and data were sought from Sanofi, the pharmaceutical company that developed and manufactures ticlopidine and clopidogrel, as well as the principal investigators of the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial,7 the largest of the trials identified. STUDY SELECTION CRITERIA: All unconfounded randomized trials comparing either ticlopidine or clopidogrel with aspirin among patients at high risk of vascular disease (those with symptoms of ischemia of the cerebral, coronary, or peripheral circulations) who were followed for at least 1 month for the recurrence of vascular events were included. DATA EXTRACTION: Data were extracted from four completed randomized trials completed in the past 20 years, which included 22,656 patients.7,10 Two authors independently extracted the data from these trials for the following information: the types of patients enrolled; the entry and exclusion criteria; the randomization method; the number of patients originally allocated to the treatment and control groups; the method and duration of follow-up; the number of patients in each group lost to follow-up; information on compliance with the treatment allocated; the definitions of outcome events; the number of outcome events in each treatment group; and any method used for blinding patients, treating clinicians, and outcome assessors to treatment allocation. MAIN RESULTS: Four completed trials involving a total of 22,656 patients were identified. Aspirin was compared with ticlopidine in three trials (3,471 patients)8,10 and with clopidogrel in one trial (19,185 patients).7 A recent TIA or ischemic stroke was the qualifying event in 9,840 patients, a recent myocardial infarction in 6,302 patients, and symptomatic peripheral arterial disease in 6,514 patients. The average age of the patients was approximately 63, with approximately two-thirds of the patients being male and white. The duration of follow-up ranged from 12 to 40 months. CONCLUSIONS: This systematic review demonstrates that, compared with aspirin, thienopyridines are only modestly more effective in preventing serious vascular events in high-risk patients. For patients who are intolerant of, or allergic to aspirin, the available safety and efficacy data suggest that clopidogrel is an appropriate, but more-expensive, alternative antiplatelet drug. It appears safer than ticlopidine and as safe as aspirin but it should not replace aspirin as the first-choice antiplatelet agent for all patients. Further studies are necessary to determine which, if any, particular types of patients would benefit most and least from clopidogrel instead of aspirin. [source] Smoking behaviour modulates pharmacokinetics of orally administered clopidogrelJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 4 2008A.-M. Yousef PhD Summary Background and objectives:, Clopidogrel is an important antiplatelet drug that is effective in preventing thrombotic events, especially for patients undergoing percutaneous coronary intervention. The therapeutic usefulness of clopidogrel has been limited by documented inter-individual heterogeneity in platelet inhibition, which may be attributable to known clopidogrel pharmacokinetic variability. The objective of this study was to assess the influence of smoking cigarettes and abnormal body weight on the pharmacokinetics of clopidogrel. Methods:, Seventy-six healthy adult male volunteers were selected randomly. Each subject received a single 75 mg oral dose of clopidogrel after overnight fast. Clopidogrel carboxylate plasma levels were measured and non-compartmental analysis was used to determine peak plasma concentration (Cmax), time to peak plasma concentration (Tmax), elimination half-life (t1/2e), and area under the curve (AUC0,,). Results:, One-third of volunteers were smokers (n = 27) and one-half had abnormal body weight (n = 39). Smokers had lower AUC0,, (smokers: 6·24 ± 2·32 ,g/h/mL vs. non-smokers: 8·93 ± 3·80 ,g/h/mL, P < 0·001) and shorter half-life (smokers: 5·46 ± 2·99 vs. non-smokers: 8·43 ± 4·26, P = 0·001). Smoking behaviour had no influence on Cmax (P = 0·3) and Tmax (P = 0·7). There was no statistically significant difference in Cmax, AUC0,,, Tmax and t1/2e between volunteers with abnormal body weight and normal body weight. However the difference in body weight of the two groups was relatively narrow (mean ± SE; 26·93 ± 0·16 vs. 23·11 ± 0·27). In general, the pharmacokinetic parameters were characterized by considerable inter-individual differences (Cmax = 3·09 ± 0·99 ,g/mL, CV = 32%), (Tmax =0·76 ± 0·24 h, CV = 31·6%), (AUC0,, = 7·98 ± 3·58 ,g/h/mL, CV = 44·8%), and (t1/2e = 7·38 ± 4·10 h, CV = 55·6%). Conclusion:, Smoking is a significant factor affecting the pharmacokinetics of clopidogrel, following administration of a single 75 mg dose in healthy young volunteers. The study supports smoking-cessation recommendations. Further studies are required to evaluate the influence of smoking and body weight on the pharmacokinetics of the active metabolite of clopidogrel and on the clinical effects of any differences observed. [source] Attitudes to prescription of antiplatelet drugs by diabetes health workersPRACTICAL DIABETES INTERNATIONAL (INCORPORATING CARDIABETES), Issue 8 2007A Woodward RN, MPhill Diabetes Specialist Nurse Abstract The aim of this survey was to explore the attitudes to antiplatelet drug use amongst a group of UK diabetes specialist medical and nursing personnel. A postal questionnaire survey was circulated to all consultant diabetologists, specialist registrars in diabetes and diabetes specialist nurses working in the Mersey Deanery area. Seventy-eight questionnaires were sent out, 63 (81%) returned. The perceived use of antiplatelet therapy was significantly higher for type 2 diabetes compared with type 1 diabetes, especially in the absence of complications or cardiovascular risk factors (52% vs 21%, p = 0.0004). Responses were more variable for type 1 diabetes: more nurses than doctors advised antiplatelet drugs in the absence of risk factors (46% vs 5%, p = 0.0002) and in the presence of smoking (79% vs 51%, p = 0.034). Aspirin was first-line choice of antiplatelet drug; clopidogrel was generally used for gastric intolerance and aspirin allergy. We conclude that the combination of limited evidence base and imprecise guidelines is not favouring proper usage of antiplatelet drugs and that more evidence-based didactic guidelines are required. Copyright © 2007 John Wiley & Sons. [source] Antiplatelet drug use preceding the onset of intracerebral hemorrhage is associated with increased mortalityFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2007Karine Lacut Abstract Recent studies highlight the contribution of antiplatelet therapy to clinical severity and increased mortality of intracerebral hemorrhage (ICH) but results are discrepant. The aim of this report was to evaluate the association between antiplatelet drug use preceding the onset of ICH and the mortality, assessed at regular intervals, among patients with acute ICH. We analyzed data from a randomized study which enrolled consecutive patients with a documented acute ICH to evaluate the efficacy of intermittent pneumatic compression of the legs in venous thrombosis prevention. Clinical characteristics and treatment used before the onset of ICH were checked at the time of inclusion. Mortality was assessed at regular intervals until 3 months after ICH diagnosis. Among 138 patients included in this report, 30 were current users of antiplatelet therapy at the time of ICH; they were significantly older and less frequently heavy drinkers than non-users of antiplatelet drugs. Mortality rates were 20% at 8 days, 40% at 1 month, and 47% at 3 months among antiplatelet drug users compared with 6.5%, 13% and 19% among non-users. The corresponding estimated risks for mortality related to antiplatelet drug use were 3.6 (95% CI 1.1,12), 4.5 (95% CI 1.8,11), and 3.6 (95% CI 1.5,8.6). Adjusted for age, hypertension and alcohol over use, antiplatelet therapy remained significantly associated with an increased mortality rate of acute ICH. Current antiplatelet drug use preceding the onset of ICH is associated with increased short-term ICH mortality, independently of age. [source] Platelet aggregation is significantly associated with cardiovascular mortality in elderly patientsGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 4 2004Kyoko Kin Background: The relationship between cardiovascular mortality and platelet function in elderly patients remains unclear. Methods: The outcomes for 347 consecutive patients aged 60 or older (mean age 77.5 years; 161 men and 186 women) who were treated without antiplatelet drugs on registration, were retrospectively studied after platelet aggregatability tests. The grading curve (GC) type, as an index of platelet aggregatability, was determined with an aggregometer and adenosine-5,-diphosphate as an agonist. Patients were classified into three groups according to GC type: Group I with suppressed aggregation (n = 40); Group II, normal aggregation (n = 208); and Group III, increased aggregation (n = 99). The mean follow-up was 3.9 years. Results: There were three deaths in Group I, 33 in Group II, and 30 in Group III. The mean annual mortality rate was 2.1% in Group I, 4.0% in Group II and 7.5% in Group III. Although the most common cause of death was pneumonia in all three groups, the annual mortality rates due to vascular events were 0.7% in Group I, 0.6% in Group II and 4.2% in Group III. Cox proportional hazards models for vascular death yielded a hazard ratio of 1.5 in the increased GC type. Conclusion: These findings indicated that elderly patients with accelerated aggregation had higher mortality rates due to vascular events. Therefore, accelerated aggregation in the elderly suggested not only the progress of arteriosclerosis, but indications of antiplatelet therapy to prevent vascular events. [source] Thrombotic thrombocytopenic purpura: 24 years of experience at the American University of Beirut Medical CenterJOURNAL OF CLINICAL APHERESIS, Issue 3 2004Ali Shamseddine Abstract Thrombotic thrombocytopenic purpura (TTP) is a hematological syndrome defined by the presence of thrombocytopenia and microangiopathic hemolytic anemia without a clinically apparent etiology. Patients may also suffer from fever in addition to neurological and renal impairment. Treatment should be initiated as soon as possible, otherwise this rare disease can be fatal. The main treatment options include therapeutic plasma exchange, fresh frozen plasma infusion, and adjuvant agents such as steroids and antiplatelet drugs. A search of patient records was carried out at the American University of Beirut Medical Center looking for patients who developed TTP over a 24-year period extending from 1980 to 2003. Relevant information was collected and analyzed. A total of 47 records were found. All presented with anemia and thrombocytopenia, 83% had neurological symptoms, 61.7% had fever and 34% had renal impairment. All patients were treated with a multimodality regimen including therapeutic plasma exchange, FFP infusion, steroids, antiplatelet agents, vincristine and others. 38 (81%) cases achieved complete remission. Out of these, 12 (31.6%) relapsed and responded to treatment. Patients who did not receive plasma exchange were more likely to relapse (P = 0.032). A second relapse was observed in 6 cases. The overall mortality rate from TTP over 24 years was 21.3%. TTP remains a fatal disease. A high index of suspicion should, therefore, always be present. Treatment options should be further developed and patients should directly be referred to tertiary care centers. J. Clin. Apheresis 19:119,124, 2004. © 2004 Wiley-Liss, Inc. [source] Function-modulating human monoclonal antibodies against platelet-membrane receptors isolated from a phage-display libraryJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2003Y. Hagay Summary., Monoclonal antibodies to platelet membrane receptors have been used extensively for analysis of receptor structure and function. Function-blocking human antibodies are being used for the development of antiplatelet drugs. We isolated human monoclonal antibodies from a library of single-chain Fv (scFv) antibodies displayed on the surface of filamentous phage, by selection on whole platelets. Eight different platelet-binding clones were isolated, of which three bound to the platelet-membrane glycoprotein (GP) GPIb in an ELISA assay. Specific elution with a recombinant polypeptide of von Willebrand factor (VWF) spanning the GPIb, binding site, yielded the same three phage clones. Two of the three anti-GPIb clones could be purified as scFv monoclonal antibodies, and they competed with each other for binding to intact platelets, suggesting that they bind at or near the same site on GPIb. Their binding affinities differed, however, and the clone with higher affinity inhibited ristocetin-induced platelet aggregation. These data indicate that selection from a phage display library of human scFvs using whole platelets can be applied for the isolation of functional antiplatelet-GPIb antibodies useful for the development of new therapeutic and diagnostic strategies. [source] Attitudes to prescription of antiplatelet drugs by diabetes health workersPRACTICAL DIABETES INTERNATIONAL (INCORPORATING CARDIABETES), Issue 8 2007A Woodward RN, MPhill Diabetes Specialist Nurse Abstract The aim of this survey was to explore the attitudes to antiplatelet drug use amongst a group of UK diabetes specialist medical and nursing personnel. A postal questionnaire survey was circulated to all consultant diabetologists, specialist registrars in diabetes and diabetes specialist nurses working in the Mersey Deanery area. Seventy-eight questionnaires were sent out, 63 (81%) returned. The perceived use of antiplatelet therapy was significantly higher for type 2 diabetes compared with type 1 diabetes, especially in the absence of complications or cardiovascular risk factors (52% vs 21%, p = 0.0004). Responses were more variable for type 1 diabetes: more nurses than doctors advised antiplatelet drugs in the absence of risk factors (46% vs 5%, p = 0.0002) and in the presence of smoking (79% vs 51%, p = 0.034). Aspirin was first-line choice of antiplatelet drug; clopidogrel was generally used for gastric intolerance and aspirin allergy. We conclude that the combination of limited evidence base and imprecise guidelines is not favouring proper usage of antiplatelet drugs and that more evidence-based didactic guidelines are required. Copyright © 2007 John Wiley & Sons. [source] Experimental Evaluation of a New Antithrombogenic Stent Using Ion Beam Surface ModificationARTIFICIAL ORGANS, Issue 6 2009Yoichi Sugita Abstract A new antithrombogenic stent using ion beam surface modification nanotechnology was evaluated. The ion stent is being developed to inhibit acute and chronic stent-related thrombosis. Thirty self-expanding mesh stents were fabricated from Ti-Ni metal wires with a dimension of 4 mm (diameter) × 25 mm (length) × 0.15 mm (thickness). Twenty stents were coated with type I collagen and irradiated with a He+ ion beam at an energy of 150 keV with fluences of 1 × 1014 ions/cm2 (ion stent group). Ten stents had no treatment (non-ion stent group). The self-expanding stents were implanted into the right and left peripheral femoral arteries of 15 beagle dogs (vessel diameter approximately 3 mm) via a 6Fr catheter under fluoroscopic guidance. Heparin (100 units/kg) was administered intravenously before implantation. Following stent implantation, no antiplatelet or anticoagulant drugs were administered. The 1-month patency rate for the non-ion stent group was 10% (1/10), and for the ion stent group it was 80% (16/20) with no anticoagulant or antiplatelet drugs given after stent implantation (P = 0.0004 by Fisher's exact test). Ten stents remain patent after 2 years in vivo with no anticoagulant or antiplatelet drugs. These results indicate that He+ ion-implanted collagen-coated Ti-Ni self-expanding stents have excellent antithrombogenicity and biocompatibility. This ion stent is promising for coronary and cerebral stent applications. [source] Antithrombotic management of ischaemic stroke and transient ischaemic attack in China: A consecutive cross-sectional surveyCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 8 2010Yi-Long Wang Summary 1.,Little is known about the prevention of secondary stroke in China. In the present study, we assessed the status of antithrombotic management of stroke patients in clinics across China. 2.,A cross-sectional survey was conducted in 19 urban neurological clinics. All subjects diagnosed with ischaemic stroke (IS) or transient ischaemic attack (TIA) were enrolled consecutively in the study. Face-to-face interviews were conducted by research assistants using questionnaires on the day of enrolment. The data recorded included demographic and clinical characteristics, medication and reasons for not using medication. Independent predictors for the prescription of antiplatelet drugs were determined using multivariate logistic regression models. 3.,Of the 2283 patients with IS or TIA enrolled in the study (34.7% women; mean ( ± SD) age 65.8 ± 11.6 years), 1719 (75.3%) had a prescription for antiplatelet therapy. Of the 108 patients with atrial fibrillation, only 14 (13.0%) were receiving warfarin therapy. The main independent factors significantly associated with being on antiplatelet therapy were having basic health insurance (odds ratio (OR) 1.47; 95% confidence interval (CI) 1.09,1.99), government insurance and labour insurance (OR 1.63; 95% CI 1.03,2.59) and a monthly income of > 500 yuan (US$66.70; OR 2.14; 95% CI 1.51,3.03). Being older (OR 0.70; 95% CI 0.50,0.99) and having a severe disability (OR 0.68; 95% CI 0.49,0.97) were associated with lower odds of receiving antiplatelet therapy. 4.,Based on the survey results, adherence to guidelines for antithrombotic management in neurological clinics in China is poor. The main reasons contributing to the less than optimal management of stroke patients include negative attitudes among neurologists, a lack of medical insurance, a lower income and being elderly and/or severely disabled. [source] | ||||||||||||||||||||||