1 Rouen University Hospital, France.
Ann Pharmacother. 2019 Apr;53(4):341-347. doi: 10.1177/1060028018811657. Epub 2018 Oct 31.
Oral anti-Xa inhibitors have demonstrated noninferiority to vitamin K antagonists (VKAs) for the prevention of stroke in patients with atrial fibrillation and recurrent venous thromboembolism. They are associated with a decrease in major bleeding. In contrast with VKA, no coagulation monitoring is required. However, in clinical practice, determination of drug concentration is sometimes necessary.
The objective of this study was to evaluate a low-molecular-weight heparin (LMWH) calibrated anti-Xa assay for the quantification of rivaroxaban and apixaban plasma concentration in emergency.
The anti-Xa plasma concentration of rivaroxaban and apixaban were measured in emergency in 210 patients using STA anti-Xa liquid assay. For each plasma concentration <150 ng/mL of rivaroxaban or apixaban, an anti-Xa assay calibrated with LMWH was performed.
We demonstrated a significant correlation between LMWH anti-Xa activity and rivaroxaban ( R = 0.947) or apixaban ( R = 0.959) concentration and a significant correlation between rivaroxaban and apixaban plasma concentration ( R = 0.972). A LMWH anti-Xa activity <0.50 IU/mL could exclude a plasma concentration of rivaroxaban and apixaban >30 ng/mL and indicate the feasibility of invasive procedure. Conclusion and Relevance: In the absence of a specific test, LMWH-calibrated anti-Xa assay could be used to determine the presence and evaluate the plasma concentration of oral anti-Xa inhibitors. However, these initial findings require confirmation using other chromogenic calibrated oral anti-Xa assays.
口服抗 Xa 抑制剂在预防心房颤动和复发性静脉血栓栓塞患者的中风方面已被证明不劣于维生素 K 拮抗剂（VKA）。它们与大出血的减少有关。与 VKA 不同，不需要进行凝血监测。然而，在临床实践中，有时需要确定药物浓度。
本研究的目的是评估一种低分子肝素（LMWH）校准的抗 Xa 测定法，用于紧急情况下定量检测利伐沙班和阿哌沙班的血浆浓度。
使用 STA 抗 Xa 液体测定法在 210 名患者的紧急情况下测量利伐沙班和阿哌沙班的抗 Xa 血浆浓度。对于每个利伐沙班或阿哌沙班的血浆浓度<150ng/mL，进行了用 LMWH 校准的抗 Xa 测定。
我们证明了 LMWH 抗 Xa 活性与利伐沙班（R=0.947）或阿哌沙班（R=0.959）浓度之间存在显著相关性，以及利伐沙班和阿哌沙班血浆浓度之间存在显著相关性（R=0.972）。LMWH 抗 Xa 活性<0.50IU/mL 可排除利伐沙班和阿哌沙班的血浆浓度>30ng/mL，并表明侵入性程序的可行性。结论和相关性：在缺乏特异性检测的情况下，可以使用 LMWH 校准的抗 Xa 测定法来确定口服抗 Xa 抑制剂的存在并评估其血浆浓度。然而，这些初步发现需要使用其他显色校准的口服抗 Xa 测定法进行证实。
