Prescrire Int. 2013 Jun;22(139):155-9.
Dabigatran, rivaroxaban and apixaban are oral anticoagulants used to prevent or treat thrombosis in a variety of situations. Like all anticoagulants, these drugs can provoke bleeding. How should patients be managed if bleeding occurs during dabigatran, rivaroxaban or apixaban therapy? How can the risk of bleeding be reduced in patients who require surgery or other invasive procedures? To answer these questions, we reviewed the available literature, using the standard Prescrire methodology. In clinical trials, warfarin, enoxaparin, dabigatran, rivaroxaban and apixaban were associated with a similar frequency of severe bleeding. Numerous reports of severe bleeding associated with dabigatran have been recorded since this drug was first marketed. Some situations are associated with a particularly high bleeding risk, including: even mild renal failure, advanced age, extremes in body weight and drug-drug interactions, particularly with antiplatelet agents (including aspirin), nonsteroidal antiinflammatory drugs, and many drugs used in cardiovascular indications. In patients treated with dabigatran, rivaroxaban or apixaban, changes in the INR (international normalised ratio) and activated partial thromboplastin time (aPTT) do not correlate with the dose. In early 2013, there is still no routine coagulation test suitable for monitoring these patients; specific tests are only available in specialised laboratories. In early 2013 there is no antidote for dabigatran, rivaroxaban or apixaban, nor any specific treatment with proven efficacy for severe bleeding linked to these drugs. Recommendations on the management of bleeding in this setting are based mainly on pharmacological parameters and on scarce experimen-Haemodialysis reduces the plasma concentration of dabigatran, while rivaroxaban and apixaban cannot be eliminated by dialysis. Prothrombin complex concentrates and recombinant activated factor VII seem to have little or no efficacy, and they carry a poorly documented risk of thrombosis. For patients undergoing surgery or other invasive procedures, clinical practice guidelines are primarily based on pharmacokinetic parameters and on extrapolation of data on vitamin K antagonists. The decision on whether or not to discontinue anticoagulation before the procedure mainly depends on the likely risk of bleeding. In patients at high risk of thrombosis, heparin can be proposed when the anticoagulant is withdrawn. In early 2013, difficulties in the management of bleeding and of situations in which there is a risk of bleeding weigh heavily in the balance of potential harm versus potential benefit of dabigatran, rivaroxaban and apixaban. When an oral anticoagulant is required, it is best to choose warfarin, a vitamin K antagonist, and the drug with which we have the most experience, except in those rare situations in which the INR cannot be maintained within the therapeutic range.
达比加群、利伐沙班和阿哌沙班是用于预防或治疗多种情况下血栓形成的口服抗凝剂。与所有抗凝剂一样,这些药物会引发出血。在达比加群、利伐沙班或阿哌沙班治疗期间发生出血时应如何处理患者?对于需要进行手术或其他侵入性操作的患者,如何降低出血风险?为回答这些问题,我们采用标准的Prescrire方法对现有文献进行了综述。在临床试验中,华法林、依诺肝素、达比加群、利伐沙班和阿哌沙班的严重出血发生率相似。自达比加群首次上市以来,已有大量与达比加群相关的严重出血报告。某些情况与特别高的出血风险相关,包括:即使是轻度肾功能衰竭、高龄、体重极端情况以及药物相互作用,特别是与抗血小板药物(包括阿司匹林)、非甾体类抗炎药以及许多用于心血管疾病的药物相互作用。在接受达比加群、利伐沙班或阿哌沙班治疗的患者中,国际标准化比值(INR)和活化部分凝血活酶时间(aPTT)的变化与剂量无关。2013年初,仍没有适用于监测这些患者的常规凝血试验;特定检测仅在专业实验室可用。2013年初,尚无针对达比加群、利伐沙班或阿哌沙班的解毒剂,也没有针对与这些药物相关的严重出血的经证实有效的特定治疗方法。关于这种情况下出血管理的建议主要基于药理学参数和稀缺的实验数据。血液透析可降低达比加群的血浆浓度,而利伐沙班和阿哌沙班不能通过透析清除。凝血酶原复合物浓缩物和重组活化因子VII似乎疗效甚微或无疗效,且它们存在记录不详的血栓形成风险。对于接受手术或其他侵入性操作的患者,临床实践指南主要基于药代动力学参数以及维生素K拮抗剂数据的外推。术前是否停用抗凝剂的决定主要取决于可能的出血风险。对于血栓形成风险高的患者,在停用抗凝剂时可考虑使用肝素。2013年初,达比加群、利伐沙班和阿哌沙班在出血管理以及存在出血风险情况的管理方面的困难,在潜在危害与潜在益处的权衡中占很大比重。当需要口服抗凝剂时,除了那些罕见的INR无法维持在治疗范围内的情况外,最好选择华法林,一种维生素K拮抗剂,也是我们最有经验的药物。