

With the RE-LY trial, dabigatran became the first FDA approved oral anticoagulant for the prevention of systemic thromboembolism and stroke in nonvalvular atrial fibrillation. After oral administration it converts to dabigatran, which is a reversible inhibitor of activated thrombin. Dabigatran and idarucizumabĭabigatran is a direct thrombin inhibitor administered as a low molecular weight prodrug dabigatran etexilate mesylate. Also this method does not neutralize the risk of thromboembolism. However this rationale is yet to be proven by studies. These agents are supposed to reverse the effect of the novel oral anticoagulants by saturating their action. The four Factor PCC also contains Factor VII. This lack of antidote limits the use of TSOAs despite their many benefits.Īt present, reversal of TSOAs is usually attempted by the administration of prothrombin complex concentrates (PCC). Certain groups of patients on anticoagulation, such as the elderly with a fall, or those needing emergent surgeries or encountering trauma will need immediate reversal of anticoagulation. Kham recently reported a case of spontaneous cardiac tamponade within 10 days of starting rivaroxaban on a patient. However, an increase in gastrointestinal bleeding was observed. More importantly the incidence of intracranial hemorrhage was reduced by almost 50 % and there was a significant reduction in all cause mortality. They were found to be equally effective in the prevention of stroke. did a meta-analysis comparing the safety and efficacy of the four newer oral agents to warfarin in patients with atrial fibrillation. Various trials comparing warfarin to either dabigatran or any of the Factor Xa inhibitors proved that the newer agents had significantly lower bleeding risk. The development of TSOAs accelerated in the last decade. Target specific oral anticoagulants and the risk of bleeding

In this review we summarized studies on antidotes to the target specific oral anticoagulants, their mechanism of action and their potential in changing the future of anticoagulation. These include idarucizumab, andexanet alpha and PER977. Currently there are a few promising antidotes undergoing clinical trials. Unlike warfarin, there is no antidote for these newer agents. Nevertheless bleeding is still a relevant side effect and their biggest drawback has been the lack of a reliable reversible agent. These drugs are prescribed in fixed doses and have fewer incidents of intracranial hemorrhage in comparison to warfarin in large randomized phase III studies. They have been approved for prevention of stroke in nonvalvular atrial fibrillation, and recently in prevention of recurrent deep vein thrombosis and pulmonary embolism. Edoxaban has most recently joined the rest. It was soon followed by Factor Xa inhibitors-rivaroxaban and apixaban. In 2010, dabigatran, a direct thrombin inhibitor, became the first target specific anticoagulant approved by FDA. These drawbacks and limitations fuelled the development of newer agents. There were various limitations like its narrow therapeutic index, food and drug interactions, need for regular monitoring and frequent dose adjustments. Warfarin, a vitamin K antagonist (VKA), was the only oral anticoagulant for more than half a century.
