Associated fatal bleeding 0.8% per year and nonfatal major bleeding and total bleeding complications occur at a rate of 2.0% and 6% per year, respectively.
Risk as with oral anticoagulants increased with advancing age, history of stroke, gastrointestinal bleeding or heart disease, concurrent aspirin therapy, atrial fibrillation, renal insufficiency, long duration of anticoagulation therapy and hypertension.
A 6-week regimen is currently recommended for isolated calf deep vein thrombosis and a 3- to 6-month treatment is recommended for proximal deep vein thrombosis or for pulmonary embolism.
PROLONG study compared individuals with at least 3 months of treatment with vitamin K antagonists for unprovoked thromboembolic disease with continued anticoagulation or not based on d-dimer levels at one month after discontinuance of the oral anticoagulant.
PROLONG study revealed that a high recurrence rate of venous thromboembolism of 15% for patients with elevated d-dimer levels and not given further anticoagulation, while patients with high levels of d-dimer given continued anticoagulation has a combined risk of recurrent venothromboembolism and bleeding of 2.9%.
PROLONG study rate of recurrent thromboembolism for patients with normal d-dimer levels and no further anticoagulation was 6.2%.
Bleeding risk is related to the intensity of anticoagulation and increases significantly above an international normalized ratio (INR) of 5.0.
Excessive anticoagulation can be corrected with the use of Vitamin K. Recommended doses are 1.0-1.25 mg for INR<9 and 3-5 mg for INR>9.
Concurrent use with NSAID’s is relatively contraindicated since the latter drugs can inhibit platelet aggregation and prolong bleeding time.
Major bleeding in cancer patients with anticoagulation treatment is 2.5-6 times higher than in patients without cancer.