截至1 5笔划的结果atrial fibrillation (AF)，导致不正常的心脏节律的条件。对于超过60年，诊断为房颤患者已处方华法林，血液稀释剂，可以显著降低risk of stroke。但是，华法林，品牌下香豆素和Jantoven销售，与和周围的脑出血的高风险相关联。
Today, there are more anticoagulant options for lowering the risk of stroke, and they are increasingly being used as alternatives to warfarin. Since 2010, the Food and Drug Administration (FDA) has approved four additional oral anticoagulant drugs that are considered at least as effective as warfarin and pose what the FDA considers an acceptable risk of bleeding. In particular, the newer drugs are less likely than warfarin to cause bleeding in the brain that leads to stroke.
New antidote
Nonetheless, all anticoagulants increase bleeding risk. When the newer drugs were first approved, medical experts were especially concerned that no antidote existed to reverse their blood-thinning effects.
However, a milestone was reached in the evolution of anticlotting drugs in 2015 when theFDA批准的逆转剂to counteract the effects of dabigatran (Pradaxa).
解毒剂，idarucizumab（Praxbind），可阻止无法控制的出血，如可能导致Pradaxa的抗凝作用，在可能危及生命的紧急情况下的那种。因此，它提供了一种用于患者的保护层。
其他新anticoagulants-Xarelto (rivaroxaban), Eliquis (apixaban), and Savaysa (edoxaban)—doctors have turned to off-label use of a coagulation factor product, prothrombin complex concentrate, for reversal of bleeding.
Here are some points to consider when discussing treatment options with your doctor. It’s important to remember that most of the bleeding that occurs with anticoagulants is not serious, and does not cause the kind of permanent disability or death that strokes cause.
Warfarin’s role
Warfarin, approved by the FDA in 1954, has been widely used to inhibit clot formation or prevent recurring episodes in people who have already developed a clot. Warfarin works by blocking an enzyme needed by the liver to produce substances that form blood clots (clotting factors).
For people with atrial fibrillation, warfarin has been shown to reduce the risk of stroke by two-thirds. Yet warfarin may also double the risk of intracranial hemorrhage—an accumulation of blood in the skull.
Warfarin is a difficult drug to manage, requiring patients to have frequent blood tests to determine if the prescribed dosage is sufficient to prevent blood clots, yet isn’t increasing the risk of excessive bleeding.
Several types of reversal agents, however, have been developed to counteract the effects of warfarin. If uncontrolled bleeding does occur due to a serious injury, these antidotes, including vitamin K and the drug Kcentra (prothrombin complex concentrate, human), can restore coagulation in people taking warfarin.
Ongoing review
Pradaxa, the first of the four most recent blood thinners to have been approved by the FDA, works by blocking an enzyme called thrombin, which is involved in the formation of blood clots.
Anongoing review by the FDA, based on information from more than 134,000 Medicare patients from 2010 to 2012, found that Pradaxa was associated with a lower risk of clot-related strokes, bleeding in the brain, and death, when compared with warfarin.
Pradaxa用11.3凝块有关的中风发病率为（发生在一定的人群的可能性）相关联的，相对于13.9为华法林。Pradaxa有颅内出血的3.3事件的速度，与9.6相比，华法林。
The FDA review also found that Pradaxa was associated with an increased risk of major gastrointestinal bleeding, when compared with warfarin—a risk that has been shown to increase with age. The incidence rate of GI bleeding in patients taking Pradaxa was 34.2, versus 26.5 for warfarin. Both drugs had a similar risk of causing heart attacks.
尽管这些调查结果，美国食品药品管理局仍然认为Pradaxa有“良好的效益对风险状况。”FDA尚未责成药品生产企业要对当前标签或使用建议的任何变化。
Reducing stroke risk
The other newer anticoagulants work by inhibiting a clotting protein called factor Xa. After evaluating clinical trials involving more than 50,000 people from around the world, the FDA concluded that all four newer drugs either had the same impact or were more effective in preventing stroke compared with warfarin, and did not cause an unacceptable risk of bleeding.
美国食品药物管理局报告说，该药物具有比引起出血，导致出血性中风的类型的华法林的危险大大降低。较新的抗凝血剂提供了其他好处，包括食物和其他药物，起效更快更少的相互作用，以及缺乏必要进行定期血液监测。
虽然致命性出血是在服用血液稀释剂患者少见，有研究表明，通过采取任何较新的抗凝血剂引起的出血的死亡率低于它是从华法林。
虽然拜瑞妥，Eliquis和Savaysa没有做FDA批准的可用于抵消其影响逆转剂，大型临床试验已经确定，所有在房颤中使用的抗凝血剂，预防中风的益处胜过出血的风险增加。
FDA monitoring of the new medications continues as reversal agents make their way through the development pipeline. At least two drugs that may reverse the effects of these anticoagulants have been undergoing clinical trials.
Preventive measure
只有大约3亿人在美国谁拥有房颤使用抗凝血剂的一半。房颤谁是抗凝血剂的候选人和没有使用这些病人没有的保护，具有毁灭性中风的高风险。
抗凝剂的方案启动后，许多患者最终以他们不到半年的时间，而不是在长期推荐。随着新的抗凝血药物，但符合条件的患者现在有更多的治疗选择。
Find out more about how you canprevent a stroke.