Thromboembolism prevention

Higher aspirin doses of 900 to 1,500 mg per day have not been shown to have increased efficacy in arterial thromboembolism prevention when compared with 300 mg per day or lower doses. In one metaanalysis of 19 antiplatelet trials in several thrombotic disorders, the issue of aspirin dosage was indirectly analyzed (44). It was found that trials employing 900 to 1,500 mg of daily aspirin versus placebo had similar outcomes to trials employing doses of 300 to 325 mg per day versus placebo. Patients treated with 900 to 1,500 mg experienced a 23% reduction in new vascular events, whereas those taking 320 mg showed a decrease of 24%. Thus a dose-response plateau appears to exist in aspirin s antithrombotic effect. Clinical and laboratory observations are complimentary in this reqrect since aspirin inhibition of in vitro platelet PG synthesis shows a similar dose-re nse plateau with maximal blockade at micromolar concentrations (2,25,28). 

Eikelboom JW, Quinlan DJ, O Doimell M. Major bleeding, mortality, and efficacy of fondaparinux in venous thromboembolism prevention trials. Circulation 2009 120(20) 2006-11. 

Due to the pivotal role of platelets in thrombus formation, especially in the arterial system, inhibition of platelet function has become a central pharmacological approach. Antiplatelet drugs are given in order to prevent and treat thromboembolic diseases such as coronary heart disease, peripheral and cerebrovascular disease. They have also revolutionized the procedures of invasive coronary interventions as they reduce the risk of restenosis and thrombosis. 

Prevention of Venous Thromboembolism in the Intensive Care Unit Patient... 

Given that VTE is often clinically silent and potentially fatal, prevention strategies have the greatest potential to improve patient outcomes.2 To rely on the early diagnosis and treatment of VTE is unacceptable because many patients will die before treatment can be initiated. Furthermore, even clinically silent disease is associated with long-term morbidity from the postthrombotic syndrome and predisposes the patient to future thromboembolic events. Despite an immense body of literature that overwhelmingly supports the widespread use of... 

Warfarin has been the primary oral anticoagulant used in the United States for the past 60 years. Warfarin is the anticoagulant of choice when long-term or extended anticoagulation is required. Warfarin is FDA-approved for the prevention and treatment of VTE, as well as the prevention of thromboembolic complications in patients with myocardial infarction, atrial fibrillation, and heart valve replacement. While very effective, warfarin has a narrow therapeutic index, requiring frequent dose adjustments and careful patient monitoring.15,29... 

Geerts WH, Pineo GF, Heit JA, et al. Prevention of venous thromboembolism The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004 126 338SM 00S. 

Combined estrogen plus progestin should not be used in the prevention of chronic diseases because it increases the risk of CHD, stroke, breast cancer, and venous thromboembolism. 

HRT should not be prescribed to women with a history of or active thromboembolic disease, breast cancer or estrogen-dependent neoplasm, pregnancy, liver disease, or undiagnosed vaginal bleeding. It also should not be used for the prevention or treatment of cardiovascular disease, cerebrovascular disease, or dementia.11... 

CHD is the leading cause of death among women in the United States. Retrospective data indicated that HRT was associated with a decrease in risk of CHD by 30% to 50%.21 However, the results of recent RCTs demonstrate that HRT does not prevent or treat CHD in women and that it actually may cause an increase in CHD events. The HERS, published in 1998, was the first RCT conducted in women with established CHD. This trial demonstrated an increased incidence of CHD events within the first year of treatment with HRT and an increased risk of venous thromboembolism (VTE) and gallbladder disease. There was a trend of decreasing incidence... 

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