Antidote to NOACs
The lack of an antidote to NOACs has been a major concern in the debates about their use in clinical practice. Most often, bleeding due to NOAC is mild to moderate and responds to the usual supportive or anti-hemorrhagic management treatment as with warfarin, for which the ‘antidote’ – intravenous vitamin K is far from ideal. Nonetheless, the antidote matter has a clear clinical relevance when dealing with severe haemorrhage or during emergent surgery. A solution to the problem seems to offer the humanised monoclonal antibody fragment (idarucizumab) with has much higher binding affinity to thrombin than dabigatran, no procoagulant or anticoagulant effect and rapid onset of action. The product is already available on the market as dabigatran antidote. 20 Other antidotes targeting factor X and/or other coagulation components are under advanced research.
Selecting the right NOAC for each patient
Selecting the right NOAC for the each patient is probably one of the most challenging problems of current clinical practice for prevention of embolism in AF. A complicated stochastic multi- acceptability criteria evaluation comparing the benefit–risk balance across current antithrombotic therapies in AF patients 21 revealed a net favourable profile of NOAC compared with other anti-thrombotic drugs across a wide range of assumptions regarding the relative importance of clinical events. In clinical practice it seems that the preference for one NOAC or another is actually mainly based on the perceived relative importance of clinical profile of the patient. There have been several attempts to individualise NOAC therapy based on pharmacological criteria, 22 accumulated real-life experience, RCT results or Summary of Product Characteristics (SmPC) descriptions. However, so far no single approach has been validated for practice and presently the best approach seems to be balanced between current knowledge summarised in the available guidelines, 19 doctor’s experience and the clinical profile and preference of the patient.