Crowther M A, Julian J, McCarty D, Douketis J, Kovacs M, Biagoni L, Schnurr T, McGinnis J, Gent M, Hirsh J, Ginsberg J
Department of Medicine, McMaster University, Hamilton, ON, Canada.
Lancet. 2000 Nov 4;356(9241):1551-3. doi: 10.1016/S0140-6736(00)03125-1.
Warfarin-associated coagulopathy is a frequent clinical complication. We aimed to assess whether treatment with vitamin K is safe and more effective than placebo in rapidly lowering the international normalised ratio (INR) into the therapeutic range in over anticoagulated patients receiving warfarin.
We did a multicentre, double-blind, placebo-controlled, randomised trial in five tertiary care hospitals. In this study, patients receiving warfarin who had an INR value between 4.5 and 10.0, and who did not have an indication for the immediate normalisation of their INR, had their warfarin withheld, and were randomly allocated to receive either 1 mg of vitamin K or placebo orally. The primary outcome measure was the INR value on the day after treatment. Secondary outcome measures included INR values on subsequent days, and the risk of haemorrhage and recurrent thrombosis over a 3 month follow-up period.
Patients given vitamin K had a more rapid decrease in the INR than those given placebo (25 of 45 (56%] vs nine of 44 [20%] patients with INR values of 1.8-3.2 on the day after treatment, respectively, p=0.001; odds ratio [OR] 0.21, 95% CI 0.07-0.57). Fewer patients given vitamin K had bleeding episodes during the follow-up period than those given placebo (two [4%] vs eight [17%] patients, respectively, p=0.050; OR 0.87, 95% CI 0.019-0.999).
Low dose oral vitamin K is more effective than placebo for the rapid lowering of raised INR values in patients taking warfarin.
华法林相关凝血障碍是一种常见的临床并发症。我们旨在评估在接受华法林治疗的抗凝过度患者中，维生素K治疗在迅速将国际标准化比值（INR）降至治疗范围内是否比安慰剂更安全、更有效。
我们在五家三级护理医院进行了一项多中心、双盲、安慰剂对照的随机试验。在本研究中，接受华法林治疗且INR值在4.5至10.0之间、且无立即将INR值正常化指征的患者停用华法林，并被随机分配口服1mg维生素K或安慰剂。主要结局指标是治疗后第二天的INR值。次要结局指标包括后续几天的INR值，以及3个月随访期内出血和复发性血栓形成的风险。
给予维生素K的患者INR下降速度比给予安慰剂的患者更快（治疗后第二天，45例患者中有25例[56%]INR值为1.8 - 3.2，而44例患者中有9例[20%]，p = 0.001；优势比[OR]0.21，95%CI 0.07 - 0.57）。随访期间，给予维生素K的患者出血事件少于给予安慰剂的患者（分别为2例[4%]和8例[17%]患者，p = 0.050；OR 0.87，95%CI 0.019 - 0.999）。
低剂量口服维生素K在迅速降低服用华法林患者升高的INR值方面比安慰剂更有效。
