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Updated: Aug 9, 2026

Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood
Published on: October 12, 2012
The heterogeneity of the anticoagulant response to heparin
Difficulties in evaluating the anticoagulant effect of heparin led to studies of the rate of disappearance of its effect on the whole body partial thromboplastin time, and of its simultaneously bioassayed plasma concentration. The slope of the anticoagulant's dose-effect curve varied with each subject's baseline coagulation status, which probably accounts for the wide range of clinically observed responses to the drug. The mean rate of disappearance of bioassayed heparin was less than the mean rate of disappearance of the drug's effect on the clotting time, probably because of heparin's extensive binding to the plasma proteins which comprise its site of action. That these two kinds of rate of disappearance were found not to be correlated may also reflect the protein-binding capacity of heparin.
Difficulties in evaluating the anticoagulant effect of heparin led to studies of the rate of disappearance of its effect on the whole body partial thromboplastin time, and of its simultaneously bioassayed plasma concentration. The slope of the anticoagulant's dose-effect curve varied with each subject's baseline coagulation status, which probably accounts for the wide range of clinically observed responses to the drug. The mean rate of disappearance of bioassayed heparin was less than the mean rate of disappearance of the drug's effect on the clotting time, probably because of heparin's extensive binding to the plasma proteins which comprise its site of action. That these two kinds of rate of disappearance were found not to be correlated may also reflect the protein-binding capacity of heparin.
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