Harenberg Job, Marx Svetlana, Krämer Roland, Giese Christina, Weiss Christel
Department of Clinical Pharmacology, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany.
Blood Coagul Fibrinolysis. 2011 Dec;22(8):637-41. doi: 10.1097/MBC.0b013e328349f1d6.
Rivaroxaban and other direct factor Xa inhibitors are used at fixed doses without drug monitoring and dose adjustment. Patients may require determination of the anticoagulant effect during treatment. The aim of this study was to develop a method to reduce the differences between thromboplastin reagents and coagulation analysers for determination of the anticoagulant effect of rivaroxaban in human plasma. Purity of rivaroxaban extracted from commercially available drug was confirmed by mass spectrometry, elemental analysis and 1H-NMR spectroscopy. Coagulation times of pooled human plasma spiked with 50-900 ng/ml rivaroxaban were analysed. Thromboplastin reagents, WHO RBT/90, Innovin, RecombiPlasTin 2G, STA Neoplastin Plus, Technoclot PT Plus and Thromborel S, the manual Kolle-Hook method and the KC10 analyser were used. An international sensitivity index (ISI) was determined for each reagent and coagulation method using the RBT/90 thromboplastin reagent as reference. The orthogonal, used for the determination of the ISI of coumarin plasmas, and ordinary regression analyses were compared. The results showed than increasing concentrations of rivaroxaban prolonged coagulation values of all thromboplastin assays linearly (r (2)= 0.96 and r(2) = 0.99, respectively). The coefficient of variation between the slopes of the dilution curves and the ratios of the thromboplastin reagents were reduced using the international normalized ratio (INR) and ISI calculated for rivaroxaban. The ISIs of the thromboplastin reagents ranged from 0.73 to 1.67 as compared with the WHO reagent using the manual technique. The coefficient of variations between the thromboplastin reagents comparing the orthogonal and the ordinary regression analysis were 6.8 versus 3.7% (Kolle-Hook method, P = 0.0011) and 8.5 versus 4.8% (KC10 method, P < 0.0001). Using ISI for vitamin-K antagonist and rivaroxaban, the INRs for the rivaroxaban-containing samples were significantly different for one of five commercial thromboplastin reagents. In conclusion, the determination of an ISI for rivaroxaban using a WHO thromboplastin reagent is required for commercial thromboplastin reagents. The manual Kolle-Hook method and an ordinary linear regression analysis should be adopted.
利伐沙班和其他直接Xa因子抑制剂以固定剂量使用，无需进行药物监测和剂量调整。患者在治疗期间可能需要测定抗凝效果。本研究的目的是开发一种方法，以减少凝血活酶试剂和凝血分析仪之间在测定人血浆中利伐沙班抗凝效果时的差异。通过质谱、元素分析和1H-NMR光谱确认从市售药物中提取的利伐沙班的纯度。分析了添加50 - 900 ng/ml利伐沙班的混合人血浆的凝血时间。使用了凝血活酶试剂WHO RBT/90、Innovin、RecombiPlasTin 2G、STA Neoplastin Plus、Technoclot PT Plus和Thromborel S，手动Kolle-Hook法和KC10分析仪。以RBT/90凝血活酶试剂为参考，为每种试剂和凝血方法测定国际敏感度指数（ISI）。比较了用于测定香豆素血浆ISI的正交法和普通回归分析。结果表明，利伐沙班浓度增加使所有凝血活酶测定的凝血值呈线性延长（r(2)分别为0.96和0.99）。使用为利伐沙班计算的国际标准化比值（INR）和ISI，稀释曲线斜率之间的变异系数以及凝血活酶试剂的比值降低。与使用手动技术的WHO试剂相比，凝血活酶试剂的ISI范围为0.73至1.67。比较正交法和普通回归分析时，凝血活酶试剂之间的变异系数在Kolle-Hook法中为6.8%对3.7%（P = 0.0011），在KC10法中为8.5%对4.8%（P < 0.0001）。对于含利伐沙班的样本，使用维生素K拮抗剂和利伐沙班的ISI时，五种市售凝血活酶试剂之一的INR有显著差异。总之，市售凝血活酶试剂需要使用WHO凝血活酶试剂测定利伐沙班的ISI。应采用手动Kolle-Hook法和普通线性回归分析。
