Stentiae," and the results of careful phase 3 studies thus cannot be completely predictive of outcomes when a medication is introduced on the pharmaceutical market. With the use of warfarin, the International Normalized Ratio (INR) that has been established to indicate adequately balanced therapy is between 2.0 and 3.0. With the new oral anticoagulants, the pharmaceutical companies emphasize that it is not necessary to monitor anticoagulant effects. In studies with different doses of new oral anticoagulants, however, incidence of clinically significant bleeding complications have been directly related to the doses. Therefore, therapeutic excesses can condition bleeding risk and therapeutic limitation can increase thrombotic risk, especially when short-acting drugs such as the new oral anticoagulants are used. Hence, it is imperative to establish an appropriate method for monitoring new oral anticoagulants, setting levels of safety and effectiveness through periodic dosage and monitoring of their anticoagulant effects. Therefore, we still recommend the use of anticoagulation units for monitoring during treatment with the new oral anticoagulants. Keywords: New oral anticoagulant, NOAC, Bleeding, Laboratory controlIntroduction Chronic antithrombotic therapy involves the use of anticoagulants, antiplatelets that are given either as monotherapy or in combination for the prevention of thrombotic complications. The well-established benefits of anticoagulant therapy are significantly hampered by the possibility of major and sometimes fatal bleeding complications. These adverse effects can range from simple skin bruising and bleeding bodies in relation to the outside (epistaxis, gastroduodenal bleeding, pulmonary complications) [1,2] or can affect vital organs with temporary or permanent PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/13485127 impairment of function (intracranial hemorrhage) or death.Correspondence: draltman@arnet.com.ar Centro de Trombosis Buenos Aires, Viamonte 2008, Buenos Aires 1056, ArgentinaAnother risk of even mild bleeding complications is that they quite frequently lead to the discontinuation of the anticoagulant therapy, either by the patient or the physician. The loss of protection by the cessation of PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/7780048 the antithrombotic treatment obviously will favor the development of thromboembolic complications [3]. Until very recently, warfarin was the only oral anticoagulant medication available, and undoubtedly it was and still is considered the "gold standard" for the prevention of ischemic stroke in patients with atrial fibrillation (AF) and/or cardiac valve prosthesis in deep vein thrombosis and pulmonary embolism. Its efficacy has been well-established by several large clinical trials comparing warfarin versus placebo or antiplatelet agents [4]. This proven efficacy is seriously reduced, however, by several limitations that affect its wide clinical use [5,6]. Among the major limitations of treatment with vitamin?2014 Altman; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction 3-Nitro-6-(trifluoromethyl)pyridin-2(1H)-one in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in 4-Bromopicolinaldehyde this article, unless otherwise stated.Altman Thrombosis Journal 2014, 12:3 http://www.thrombosisjournal.com/content/12/1/.