Gosselin Robert C, Francart Suzanne J, Hawes Emily M, Moll Stephan, Dager William E, Adcock Dorothy M
University of California, Sacramento, CA, USA.
University of North Carolina, Chapel Hill, NC, USA.
Ann Pharmacother. 2015 Jul;49(7):777-83. doi: 10.1177/1060028015578451. Epub 2015 Apr 8.
Determination of plasma rivaroxaban concentration may be necessary in certain clinical situations. Rivaroxaban concentration can be accurately and rapidly determined using a chromogenic anti-activated factor X (factor Xa) assay with specific drug calibrator material. However, there are currently no Food and Drug Administration (FDA)-approved rivaroxaban calibrators available in the United States.
To determine whether FDA-approved commercial kits for measuring heparin anti-factor Xa activity can be used to assess rivaroxaban concentrations when calibrated for unfractionated heparin or low-molecular-weight heparins.
Trough and peak samples were taken from 30 patients taking rivaroxaban as part of their routine care for atrial fibrillation or venous thromboembolism. The samples were tested using 3 different FDA-approved commercial kits for measuring heparin anti-factor Xa activity.
There was acceptable correlation between rivaroxaban levels and heparin anti-factor Xa activity using Berichrom and COAMATIC heparin kits. The STA liquid heparin method was the most sensitive to presence of rivaroxaban.
This study demonstrates a strong correlation, but variability between kits, for assessing rivaroxaban concentrations using heparin anti-factor Xa assays. The extent of the heparin calibration curve significantly limits the measurable rivaroxaban range, and this application may be useful only for trough samples. The STA liquid heparin, being exquisitely sensitive to rivaroxaban, may be suitable for ruling out presence of the drug. The routine use of heparin-calibrated anti-factor Xa assays to quantify rivaroxaban is not advocated, and when applied, it must be used with caution and limitations clearly understood.
在某些临床情况下，可能需要测定血浆利伐沙班浓度。使用含特定药物校准材料的显色抗活化因子X（因子Xa）测定法可准确、快速地测定利伐沙班浓度。然而，目前美国食品药品监督管理局（FDA）尚未批准用于利伐沙班的校准品。
确定经FDA批准的用于测量肝素抗因子Xa活性的商用试剂盒，在校准用于普通肝素或低分子量肝素时，是否可用于评估利伐沙班浓度。
从30例接受利伐沙班治疗的房颤或静脉血栓栓塞患者中采集谷值和峰值样本，这些患者接受利伐沙班治疗作为其常规治疗的一部分。使用3种不同的经FDA批准的用于测量肝素抗因子Xa活性的商用试剂盒对样本进行检测。
使用贝里科姆（Berichrom）和科马蒂克（COAMATIC）肝素试剂盒时，利伐沙班水平与肝素抗因子Xa活性之间存在可接受的相关性。STA液体肝素法对利伐沙班的存在最为敏感。
本研究表明，使用肝素抗因子Xa测定法评估利伐沙班浓度时，试剂盒之间存在很强的相关性，但也存在变异性。肝素校准曲线的范围显著限制了可测量的利伐沙班范围，且这种应用可能仅对谷值样本有用。STA液体肝素对利伐沙班极为敏感，可能适用于排除药物的存在。不提倡常规使用肝素校准的抗因子Xa测定法来定量利伐沙班，如需应用，必须谨慎使用并清楚了解其局限性。
