PURPOSE: Dosing of the anticoagulant enoxaparin may result in bleeding following excessive doses or thrombosis if dose is too low. Rarely, anti-Xa activity is used to assess the dose for enoxaparin, but its utility to predict clotting or bleeding remains uncertain. We aimed to develop a clotting time test to monitor enoxaparin therapy. METHODS: A previously developed mathematical model of the coagulation network was used to identify suitable targets for monitoring enoxaparin therapy. In vitro experiments were then carried out to demonstrate proof of mechanism of the clotting time test activated by the new target activator. RESULTS: Using the mathematical model, we identified Xa as a plausible activating agent for a clotting time test for enoxaparin. In vitro experiments showed a prolongation of the Xa clotting time of 4.6-fold in the presence of enoxaparin (0.5 IU/ml) where 10 nM Xa was used to activate clotting. CONCLUSIONS: Using both simulations and in vitro experiments, we provide a proof of mechanism for the Xa clotting time (XaCT) test, which can be considered for further development to provide a biomarker of the effect of enoxaparin on the clotting system.
PURPOSE: Dosing of the anticoagulant enoxaparin may result in bleeding following excessive doses or thrombosis if dose is too low. Rarely, anti-Xa activity is used to assess the dose for enoxaparin, but its utility to predict clotting or bleeding remains uncertain. We aimed to develop a clotting time test to monitor enoxaparin therapy. METHODS: A previously developed mathematical model of the coagulation network was used to identify suitable targets for monitoring enoxaparin therapy. In vitro experiments were then carried out to demonstrate proof of mechanism of the clotting time test activated by the new target activator. RESULTS: Using the mathematical model, we identified Xa as a plausible activating agent for a clotting time test for enoxaparin. In vitro experiments showed a prolongation of the Xa clotting time of 4.6-fold in the presence of enoxaparin (0.5 IU/ml) where 10 nM Xa was used to activate clotting. CONCLUSIONS: Using both simulations and in vitro experiments, we provide a proof of mechanism for the Xa clotting time (XaCT) test, which can be considered for further development to provide a biomarker of the effect of enoxaparin on the clotting system.
Authors: Edelgard Lindhoff-Last; Meyer Michel Samama; Thomas L Ortel; Jeffrey I Weitz; Theodore E Spiro Journal: Ther Drug Monit Date: 2010-12 Impact factor: 3.681
Authors: M M Rabah; J Premmereur; M Graham; J Fareed; D A Hoppensteadt; L L Grines; C L Grines Journal: Am J Cardiol Date: 1999-12-15 Impact factor: 2.778
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Authors: M T Nurmohamed; F R Rosendaal; H R Büller; E Dekker; D W Hommes; J P Vandenbroucke; E Briët Journal: Lancet Date: 1992-07-18 Impact factor: 79.321
Authors: S Nayak; D Lee; S Patel-Hett; D D Pittman; S W Martin; A C Heatherington; P Vicini; F Hua Journal: CPT Pharmacometrics Syst Pharmacol Date: 2015-06-19