Our library of drug research abstracts drawn from the medical literature is updated on a regular schedule, and you can be assured that new coumadin research articles will be listed here shortly after becoming available to us.
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Medical research on coumadin
Pharmacogenomics. 2008 Jul; 9(7): 819-823
Ozdemir V, Dubé MP, Tardif JC, de Denus S, Phillips M, Stenne R, Shimoda K, Someya T, Godard B
Dosing Algorithms to Predict Warfarin Maintenance Dose in Caucasians and African Americans.
Clin Pharmacol Ther. 2008 Jul 2;
Schelleman H, Chen J, Chen Z, Christie J, Newcomb C, Brensinger C, Price M, Whitehead A, Kealey C, Thorn C, Samaha F, Kimmel S
The objective of this study was to determine whether warfarin dosing algorithms developed for Caucasians and African Americans on the basis of clinical, environmental, and genetic factors will perform better than an empirical starting dose of 5 mg/day. From April 2002 through December 2005, 259 subjects (Caucasians and African Americans) who started using warfarin were prospectively followed until they reached maintenance dose. The Caucasian algorithm included 11 variables (R(2) = 0.43). This model (which predicted 51% of the doses to within 1 mg of the observed dose) performed better than 5 mg/day (which predicted 29% of the doses to within 5 +/- 1 mg). The African-American algorithm included 10 variables (R(2) = 0.28). This model predicted 37% of the doses to within 1 mg of the observed dose, representing a small improvement compared with 5 mg/day (which predicted 34% of the doses to within 1 mg of 5 mg/day). These results were similar to the results we obtained from testing other published algorithms. The dosing algorithms explained
Will Warfarin Soon Be Passé? New Approaches to Stroke Prevention in Atrial Fibrillation.
J Cardiovasc Pharmacol. 2008 Jun 26;
Hammwöhner M, Goette A
Atrial fibrillation (AF) is the most common cause for thromboembolic stroke. Oral anticoagulation with warfarin is still the most effective therapy in patients with AF, who are at an increased risk for stroke. Nevertheless, warfarin therapy has several limitations; therefore, new anticoagulants like warfarin analogs, thrombin inhibitors, or factor Xa inhibitors have been developed. Some of them are currently being tested in phase III trials in patients with AF. Furthermore, the pathophysiology of prothrombotic endocardial remodeling in fibrillating atria suggests that angiotensin II increases prothrombotic expression of vascular adhesion molecules at the atrial endocardium. Thus, novel anticoagulants or hybrid therapy with a combination of anticoagulants with inhibitors of endocardial remodelling like angiotensin II receptor blockers appear to be attractive future perspective approaches.
Sublingual administration of warfarin: a novel form of delivery.
Vasc Med. 2008 May; 13(2): 123-6
Batke-Hastings S, Carman TL
AbstractCurrent therapy for venous thromboembolism (VTE) includes the initiation of short acting parenteral agents, heparin, low-molecular-weight heparin, or fondaparinux, with subsequent conversion to oral warfarin therapy for the duration of anticoagulation. We present two patients who required long-term anticoagulation for VTE but because of gastrointestinal dysmotility issues were unable to use standard oral anticoagulation. Warfarin is water soluble and absorbed across the epithelium; therefore, we elected to administer warfarin sublingually in an effort to avoid the dysmotility issues while trying to achieve therapeutic anticoagulation. Using sublingual warfarin dosing we were able to achieve therapeutic anticoagulation without complications. Both patients required approximately 6 days to achieve a therapeutic International Normalized Ratio (INR). Neither patient reported adverse side effects related to the sublingual dosing. This unique form of warfarin delivery may be considered for patients with gastrointestinal dysmotility or other gastrointestinal issues which prevent oral use of medications.
Trends in embolectomy of the extremities: a population-based study.
ANZ J Surg. 2008 Jul; 78(7): 561-3
Ponosh S, Broadhurst R, Semmens J, Norman PE
BACKGROUND: There is anecdotal evidence that fewer brachial and femoral embolectomies are being carried out. This may be because of the greater use of anticoagulation in patients with atrial fibrillation. The aim of the present study was to assess community-wide temporal trends in embolectomy of the extremities and of warfarin usage. METHODS: The Western Australian Linked Data System was used to identify cases of extremity embolectomy with a combination of diagnosis (upper or lower limb embolus) and procedure (embolectomy and revascularization) codes. Trends in age-specific and age-standardized rates were assessed over the period 1992-2003. Data regarding warfarin prescriptions were acquired from the Pharmaceutical Benefits Schedule database for the period 2000-2005. RESULTS: One thousand and five patients aged 30 years and more underwent an embolectomy of the extremity during the study period. The age-specific rate of embolectomy increased from 0.78 per 100,000 in the 30- to 49-year-old group to 46.1 per 100,000 for those aged 80 years and more. There was a significant downward trend between 1992 and 2003 (Cuzik's trend test P = 0.015). This pattern was seen for all age groups. Prescriptions for warfarin increased by 50.4% over the period 2000-2005. CONCLUSION: The rates of embolectomy of the extremity appear to be falling. Although the cause for this trend is not known, one possible explanation is increasing prescription of warfarin.
[Oral anticoagulants: warfarin or acenocumarol?]
Med Clin (Barc). 2008 Jun 21; 131(3): 98-100
Roncalés FJ
Med Clin (Barc). 2008 Jun 21; 131(3): 96-7
Oliva Berini E, Galán Alvarez P, Pacheco Onrubia AM
BACKGROUND AND OBJECTIVE: Long half life oral anticoagulants have shown a higher anticoagulation stability and a lower hemorragic risk than those of a short half life. We have compared therapeutic stability and hemorragic risk of acenocoumarol versus warfarin in 2 groups of patients on preventive anticoagulation because of atrial fibrilation (international normalised ratio [INR]: 2-3). PATIENTS AND METHOD: Data on 120 patients treated with acenocoumarol and 120 on warfarin treatment who had started and continued treatment in our hospital for a minimum of a year was collected. RESULTS: The percentage of visits within the intended range of INR (2 to 3) was 65.5% with warfarin and 63.4% with acenocoumarol. Thirty percent of patients on warfarin had 75% or more of their controls within range, while for those treated with acenocoumarol this percentage was 22.5%. In the acenocoumarol group, 0.3 visits/patient/year presented an INR >/= 6 versus 0.07 in the warfarin group (p = 0.003). CONCLUSIONS: Patients treated with acenocoumarol show a higher risk of presenting with an INR >/= 6, but no statistically significant differences are observed in therapeutic stability.
Am J Health Syst Pharm. 2008 Jul 1; 65(13 Suppl 5): S1-5
Talbert RL
PURPOSE: The role of antiplatelet therapy in preventing and treating cardiovascular disease is reviewed. SUMMARY: Cardiovascular disease, especially coronary heart disease, contributes to substantial morbidity and mortality in the United States and raises healthcare costs. Current guidelines from the American College of Cardiology and the American Heart Association, in conjunction with the Society for Cardiovascular Angiography and Interventions, recommend percutaneous coronary intervention (PCI) and stent placement to improve cardiovascular outcomes in patients with acute coronary syndrome, which encompasses unstable angina and myocardial infarction. Following stent placement, dual antiplatelet therapy with aspirin and a thienopyridine (clopidogrel or ticlopidine) significantly reduces the incidence of early major adverse cardiac events and mortality compared with aspirin alone or in combination with warfarin, and is the current standard of care for patients undergoing PCI. Maintenance therapy should be continued for at least one month after placement of a bare-metal stent, and at least three months or six months after placement of a sirolimus- or paclitaxel-eluting stent; ideally, therapy should be continued for one year following PCI. Even utilizing this standard, however, adverse clinical events do occur. In addition, treatment is often discontinued within the first year after stent placement by either the healthcare provider or the patient. CONCLUSION: Premature discontinuation of antiplatelet therapy is associated with an increased risk of adverse outcomes and can be avoided through better understanding of these risks by healthcare professionals and improved patient education.
Clin Appl Thromb Hemost. 2008 Jul; 14(3): 365-8
Küpeli E, Cengiz C, Cila A, Karnak D
Pulmonary thromboembolism is a life-threatening condition resulting mostly from lower extremity deep-vein or pelvic-vein thrombosis. A 46-year-old woman was admitted to hospital with pain on the right side of the chest and hemoptysis. On laboratory analysis, D-dimer level was elevated. Computed tomographic pulmonary angiography revealed intravascular filling defects due to thrombi in right lower lobe pulmonary segmental arteries. Screening for thrombophilic states was normal except for heterozygous mutations of both prothrombin and methylene tetrahydrofolate reductase (MTHFR 677) genes. Homocysteine level was high, and vitamin B12 level and serum ferritin level were reduced. Serum antiparietal antibody was positive, and therefore, pernicious anemia was diagnosed along with iron-deficiency anemia. After the diagnoses were established, enoxaparin followed by warfarin was started in addition to oral vitamin B12, pyridoxine, thiamine, folic acid, and ferroglycine sulfate supplementation. At the end of 8 weeks of the replacement therapy, vitamin B12, folate, and homocysteine levels and red cell volume were found to be normal, with complete resolution of the thrombus confirmed by repeat computed tomographic pulmonary angiography. We conclude that hyperhomocysteinemia due to vitamin B12 deficiency associated with pernicious anemia might have decreased the threshold for thrombosis. In addition, the presence of heterozygous prothrombin and methylene tetrahydrofolate reductase mutations might serve as synergistic cofactors triggering pulmonary thromboembolism.
Rev Med Interne. 2008 Jun 25;
Wahl D, Perret-Guillaume C, Piette JC
The antithrombotic therapy of the antiphospholipid syndrome (APS) has long been based on an empirical strategy. In the absence of appropriate randomised controlled trials, data of retrospective cohort studies were used to establish these strategies. Here we report the results of recent clinical trials, what they add to patient management and the issues that remain unsolved. SECONDARY PROPHYLAXIS OF THROMBOTIC EVENTS: While there is a consensus for prolonged vitamin K antagonist anticoagulation after a first event, two recent randomised clinical trials have compared various intensities of anticoagulation. Both studies have shown that high intensities of warfarin were not superior to conventional intensities. Patients included in these studies had mainly venous thromboembolic events. There has been no study comparing different antithrombotic strategies for arterial thrombosis associated with APS. The WARSS/APASS study, in particular has not been conducted in patients with definite APS and should not be applied to these patients. For now, vitamin K antagonist anticoagulants should remain the treatment of choice in these patients. PRIMARY PROPHYLAXIS OF THROMBOTIC EVENTS: Because of the high incidence of thrombotic events in asymptomatic patients with antiphospholipid antibodies, especially in systemic lupus erythematosus, a clinical trial compared aspirin and placebo in this setting. This study did not demonstrate any benefit of aspirin. We conclude that recent clinical trials indicate the optimal antithrombotic strategy in APS with venous thromboembolism. However, the best options for patients with arterial thrombosis and for primary prophylaxis remain to be established by further studies.