Establishing a therapeutic range for heparin therapy
Standardization of activated partial thromboplastin time (aPTT) results may be accomplished using protamine titration heparin levels of 0.2 to 0.4 U per milliliter of blood. Heparin is an anticoagulant used to treat patients with blood clotting disorders. The proper dosage of heparin is calculated from the aPTT, an intrinsic measurement of the blood clotting pathway. A study compared two methods for calculating the therapeutic range of aPTT results using blood samples from patients treated with intravenous heparin for blood clotting disorders. The most effective method involved the use a minimum heparin level of 0.2 U per milliliter of blood based on protamine titration. A varied response to heparin occurred between different aPTT reagents and lin aPTT reagent lots from the same company.
Publication Name: Annals of Internal Medicine
A comparison of three months of anticoagulation with extended anticoagulation for a first episode of idiopathic venous thromboembolism
People who have had one episode of venous thromboembolism should be treated with anticoagulant drugs for longer than three months. Venous thromboembolism occurs when blood clots form in the legs and travel to other parts of the body. Normally, when people have a first occurrence they are treated with anticoagulants for three months. Researchers randomly assigned 162 patients who had been treated for three months to continue taking warfarin or a placebo. Warfarin treatment beyond three months reduced the risk of a recurrence by 95% compared to placebo.
Publication Name: The New England Journal of Medicine