Venous thromboembolism warfarin

Patients with cancer who develop a venous thromboembolism may benefit from long-term therapy with a low molecular weight heparin (at least the first 3-6 mo of pharmacotherapy) instead of oral warfarin... 

FIGURE 7-8. Pharmacologic activity and metabolism of warfarin. CYP, cytochrome P-450 isoenzyme. (Reproduced from Haines ST, Zeolla M, Witt DM. Venous thromboembolism. In DiPiro JT, Talbert RL, Yee GC, et al, (eds.) Pharmacotherapy A Pathophysiologic Approach. 6th ed. 

Wittkowsky AK. Why warfarin and heparin need to overlap when treating acute venous thromboembolism. Dis Mon 2005 51 112-5. 

Warfarin readily crosses the placenta. It can cause hemorrhage at any time during pregnancy as well as developmental defects when administered during the first trimester. Therefore, venous thromboembolic disease in pregnant women is generally treated with heparin, best administered by subcutaneous injection. 

Francis CW, Berkowitz SD, Comp PC, et al, Comparison of ximelagatran with warfarin for the prevention of venous thromboembolism after total knee replacement. N EnglJ Med 2003 349 1703-1712. 

Cost-effectiveness analysis is concerned with how to attain a given objective at minimum financial cost, e.g. prevention of postsurgical venous thromboembolism by heparins, warfarin, aspirin, external pneumatic compression. Analysis includes cost of materials, adverse effects, any tests, nursing and doctor time, duration of stay in hospital (which may greatly exceed the cost of the drug). 

Kovacs MJ, Rodger M, Anderson DR, et al. Comparison of 10 mg and 5 mg warfarin initiation nomograms together with low-molecular-weight heparin for outpatient treatment of acute venous thromboembolism A randomized, double-blind, controlled trial. Ann Intern Med 2003 138 714-719. 

Ridker PM, Goldhaber SZ, Danielson E, et al. Long-term, low-intensity warfarin therapy for the prevention of recurrent venous thromboembolism. N Engl J Med 2003 348 1425-1434. 

Meyer G, Marjanovic Z, Valcke J, Lorcerie B. Comparison of low-molecular-weight heparin and warfarin for the secondary prevention of venous thromboembolism in patients with cancer. Arch Intern Med 2001 162 1729-1735. 

Consider also that, from a disease perspective, when treating venous thromboembolic disease in patients with eancer, warfarin is generally in-... 

A 55-year-old woman with systemic lupus erythematosus, chronic renal insufficiency, IgA deficiency with anti-IgA antibodies, an anaphylactic reaction after infusion of albumin, and venous thromboembolism took warfarin... 

Warfarin has been the mainstay of oral anticoagulant therapy for many years, principally for atrial fibrillation, mechanical heart valves, or venous thromboembolism. Adverse-effects profile of patients on warfarin therapy parallel what would be seen in vitamin K deficiency. Dne to its inhibitory effect on VKOR in the liver, warfarin affects the fnnction of the MGP and has been associated with vascular calcification in various animal and human studies. 

The comprehensive review by Douglas provides a recent discussion of the clinically useful anticoagulants. Recent studies have shown heparin to be clearly effective in clinical states In which disseminated Intravascular coagulation was Indicated to be a pathologic factor.75 xhe most commonly employed oral anticoagulants are of the coumarin type such as warfarin and nicoumalone. The oral anticoagulants appear to be of value in the prevention of thromboembolic complications after myocardial infarction.9 76 However, anticoagulation therapy has been found to have no effect on death-rate in these patients.77 Warfarin has been shown to be effective in the prevention of postoperative venous thrombosis. 

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