Landspitali/The National University Hospital of Iceland, Reykjavik, Iceland.
Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
Int J Lab Hematol. 2019 May;41 Suppl 1:40-48. doi: 10.1111/ijlh.13008.
Vitamin K antagonists (VKAs) cannot be administered without regular monitoring in order to assure their efficacy and safety. Indeed, if well managed, the VKAs appear to be no less efficacious or safe than the newer direct oral anticoagulants (DOACs). Although it is claimed that no regular monitoring of the DOACs is needed, their levels are increasingly being measured under a variety of circumstances, for example, prior to surgery, in suspected overdose, to confirm effective reversal, in patients with malabsorption and to assess patient compliance. Although no therapeutic range has been identified for the DOACs, it has been demonstrated for dabigatran and edoxaban that their antithrombotic effect increases gradually with increasing concentrations and that the risk of major bleeding also gradually increases. Furthermore, it has been determined that almost all dabigatran-related thrombotic events occur in patients with the lowest quartile concentration of the drug. This suggests that to assure an ideal effect of DOACs in all patients taking them, some form of regular monitoring and dose tailoring should be performed. For the vitamin K antagonists, the best outcome is obtained using formal algorithms and centralized management. Furthermore, data suggest that replacing the standard prothrombin time as a monitoring test may increase the stability of VKA anticoagulation with consequent reduction in thromboembolism without an increase in bleeding. Thus, it is likely that the outcome of all current oral anticoagulants can be improved in the coming years by improving monitoring and tailoring their effect.
维生素 K 拮抗剂（VKAs）在使用时需要定期监测以确保其疗效和安全性。实际上，如果管理得当，VKAs 的疗效和安全性并不逊于新型直接口服抗凝剂（DOACs）。尽管据称 DOACs 不需要常规监测，但在各种情况下（例如手术前、疑似过量时、确认有效逆转时、在吸收不良的患者中以及评估患者依从性时），其水平越来越多地被测量。虽然尚未确定 DOACs 的治疗范围，但已经证明达比加群和依度沙班的抗血栓作用随着浓度的增加而逐渐增加，大出血的风险也逐渐增加。此外，几乎所有与达比加群相关的血栓事件都发生在药物浓度最低的四分之一患者中。这表明，为了确保所有服用 DOACs 的患者都能获得理想的效果，应该进行某种形式的定期监测和剂量调整。对于维生素 K 拮抗剂，使用正式的算法和集中管理可以获得最佳效果。此外，数据表明，用标准化凝血酶原时间替代监测测试可能会提高 VKAs 抗凝的稳定性，从而减少血栓栓塞而不增加出血。因此，通过改善监测和调整其效果，所有当前口服抗凝剂的效果在未来几年都有可能得到改善。
