The NOACs: clinical pharmacology

ESC CardioMed ◽  
2018 ◽  
pp. 268-272
Author(s):  
Jeffrey Weitz

The limitations of vitamin K antagonists prompted the development of new oral anticoagulants that could be administered in fixed doses without routine coagulation monitoring. Focusing on thrombin and factor Xa because of their prominent roles in coagulation, structure-based design led to the development of small molecules that bind to the active site pockets of these enzymes with high affinity and specificity. Four non-vitamin K antagonist oral anticoagulants are now licensed: dabigatran, which inhibits thrombin, and rivaroxaban, apixaban, and edoxaban, which inhibit factor Xa. In phase III randomized clinical trials that included over 100,000 patients these agents have proven to be at least as effective as vitamin K antagonists for prevention of stroke in patients with non-valvular atrial fibrillation and for treatment of venous thromboembolism, and to produce less bleeding, particularly less intracranial bleeding.

Author(s):  
N. N. Kryukov ◽  
E. V. Sayutina ◽  
A. M. Osadchuk ◽  
M. A. Osadchuk

Patients with atrial fibrillation have a high risk of developing stroke and death, which requires constant anticoagulant support. In this regard, the physician faces the difficult task of selecting the appropriate oral anticoagulant for patient with individual risk factors and comorbidities. Currently, three non-vitamin K antagonist oral anticoagulants or directly acting oral anticoagulants have been registered in the Russia, which in large randomized clinical trials (RCTs) were compared with warfarin in the prevention of stroke and systemic embolism. The present article analyzes the data of RCTs, postmarketing studies of oral anticoagulants, and presents groups of patients for whom these drugs are preferred. The choice of oral anticoagulants for the prevention of stroke in the following subgroups of patients with atrial fibrillation is discussed: patients with one stroke risk factor (CHA2DS2VASc1 in men or 2 in women), patients of different age groups, patients with concomitant coronary artery disease/acute coronary syndrome, a history of stroke, patients with chronic kidney disease, patients with a high risk of gastrointestinal bleeding, and a group of patients with concomitant arterial hypertension and chronic heart failure. We compared the efficacy and safety of oral non-vitamin K antagonist oral anticoagulants or directly acting oral anticoagulants with vitamin K antagonists in patients with non-valvular atrial fibrillation.


Author(s):  
Kuang-Tsu Yang ◽  
Wei-Chih Sun ◽  
Tzung-Jiun Tsai ◽  
Feng-Woei Tsay ◽  
Wen-Chi Chen ◽  
...  

Background: Non-vitamin K antagonist oral anticoagulants (NOACs) are more commonly used to prevent atrial fibrillation (AF) patients from thromboembolic events than vitamin K antagonists (VKAs). However, the gastrointestinal bleeding (GIB) risk in the Asian AF patients associated with NOACs in comparison with VKAs remained unaddressed. Materials and Methods: A systematic search of studies on NOACs and VKAs in the Asian AF patients was conducted in PubMed, Cochrane Library, and ClinicalTrials.gov. The primary outcome was the hazard ratio (HR) of any GIB associated with NOACs versus VKAs. The secondary outcome was the GIB risks in different kinds of NOACs compared with VKAs. Results: This meta-analysis included two randomized controlled trials (RCTs) and four retrospective studies, comprising at least 200,000 patients in total. A significantly lower HR of GIB risks was found in all kinds of NOACs than VKAs in the Asian AF patients (HR: 0.633; 95% confidence interval: 0.535–0.748; p < 0.001). Additionally, the GIB risks of different NOACs were apixaban (HR: 0.392), edoxaban (HR: 0.603), dabigatran (HR: 0.685), and rivaroxaban (HR: 0.794), respectively. Conclusions: NOACs significantly reduced the risk of GIB in the Asian AF patients compared with VKAs. In the four NOACs compared with VKAs, apixaban probably had a trend of the least GIB risk. We need further head-to-head studies of different NOACs to confirm which NOAC is the most suitable for Asian AF patients and to know the optimal dosage regimen of different NOACs.


Kardiologiia ◽  
2019 ◽  
Vol 59 (5) ◽  
pp. 68-79
Author(s):  
L. V. Popova ◽  
T. B. Kondratieva ◽  
M. B. Aksenova ◽  
T. V. Khlevchuk ◽  
M. Z. Kanevskaya

Non-vitamin K antagonist oral anticoagulants (NOACs) – direct oral anticoagulants – are getting the ever-broadening use in clinical practice. However, many problems related to optimal use of NOACs in specific clinical situations remain unresolved. European Heart Rhythm Association in April 2018 issued the renovated recommendations on the use of NOACs in patients with atrial fibrillation. The authors of recommendations presented some specific clinical variants for which they formulated practical advices based on the evidence obtained in randomized clinical trials. They also outlined the indications for use of NOACs, formulated practical start-program and scheme of subsequent follow-up management of patients taking NOACs. Recommendations contain information on pharmacokinetics of NOACs and their interactions with other drugs, consideration of feasibility of NOACs use in patients with chronic renal insufficiency or advanced liver disease. Many other practical problems are covered as well.  


2020 ◽  
Vol 73 (11) ◽  
pp. 2528-2534
Author(s):  
Dagmara Wojtowicz ◽  
Anna Tomaszuk-Kazberuk ◽  
Jolanta Małyszko ◽  
Marek Koziński

Non-vitamin K antagonist oral anticoagulants (NOACs) are currently recommended for oral anticoagulation in patients with non-valvular atrial fibrillation. In the setting, NOACs effectively prevent from stroke and systemic embolic events. In spite of the favorable safety profile of NOACs when compared with vitamin K antagonists, the use of any kind of anticoagulation is associated with an increased risk of bleeding. However, there is still a lack of direct comparisons of effectiveness and safety among NOACs. The results of indirect comparisons and meta-analyses suggest that the risk of various types of hemorrhagic complications differ among the particular NOACs. Management of bleeding in patients under NOAC therapy can be challenging because of limited availability of antidotes and the lack of routine laboratory test monitoring the NOAC anticoagulant effect. In case of life-threatening or critical site bleeding, reversal of NOAC anticoagulant activity is essential together with immediate implementation of causative treatment. Moreover, some patients on chronic NOAC therapy may require urgent surgery or invasive procedures. Specific reversal agents for NOACs have been developed, i.e. more widely available idarucizumab for the factor IIa inhibitor (dabigatran) and andexanet alfa for the factor Xa inhibitors (rivaroxaban, apixaban, edoxaban) with limited availability. This review summarizes the occurrence and management of NOAC-related bleeding complications with a particular emphasis on hematuria.


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Emma Kirstine Laugesen ◽  
Laila Staerk ◽  
Nicholas Carlson ◽  
Anne-Lise Kamper ◽  
Jonas Bjerring Olesen ◽  
...  

Abstract Background We aimed to compare effectiveness and safety of non-vitamin K antagonist oral anticoagulants (NOACs) versus vitamin-K antagonists (VKA) in atrial fibrillation (AF) patients with chronic kidney disease (CKD) not receiving dialysis. Methods By using personal identification numbers, we cross-linked individual-level data from Danish administrative registries. We identified every citizen with a prior diagnosis of AF and CKD who initiated NOAC or VKA (2011–2017). An external analysis of 727 AF patients with CKD (no dialysis) was performed to demonstrate level of kidney function in a comparable population. Study outcomes included incidents of stroke/thromboembolisms (TEs), major bleedings, myocardial infarctions (MIs), and all-cause mortality. We used Cox proportional hazards models to determine associations between oral anticoagulant treatment and outcomes. Results Of 1560 patients included, 1008 (64.6%) initiated VKA and 552 (35.4%) initiated NOAC. In a comparable population we found that 95.3% of the patients had an estimated glomerular filtration rate (eGFR) < 59 mL/min. Patients treated with NOAC had a significantly decreased risk of major bleeding (hazard ratio (HR): 0.47, 95% confidence interval (CI): 0.26–0.84) compared to VKA. There was not found a significant association between type of anticoagulant and risk of stroke/TE (HR: 0.83, 95% CI: 0.39–1.78), MI (HR: 0.45, 95% CI: 0.18–1.11), or all-cause mortality (HR: 0.99, 95% CI: 0.77–1.26). Conclusion NOAC was associated with a lower risk of major bleeding in patients with AF and CKD compared to VKA. No difference was found in risk of stroke/TE, MI, and all-cause mortality.


2020 ◽  
Vol 22 (Supplement_O) ◽  
pp. O28-O41
Author(s):  
Matthias Hammwöhner ◽  
Andreas Goette

Abstract Currently, four non-vitamin K antagonists oral anticoagulants (NOACs) are available for stroke prevention in atrial fibrillation (AF). These have been in clinical use for up to 10 years now. Besides data of the initial phase III clinical trials, now clinical data, several sub-studies, meta-analyses, and studies in special clinical settings and specific patient populations are available. This review shall give an overview on the history of NOAC development, sum up study data and ‘real-world’ clinical data as well as discuss several special clinical settings like NOAC treatment in patients that require coronary artery stenting or cardioversion (CV). Furthermore, treatment considerations in special patient populations like patients with renal impairment, obesity, or patients requiring NOACs for secondary prevention are discussed. The significance of NOAC treatment will be discussed under consideration of the recently published 2020 ESC/EACTS Guidelines for the diagnosis and management of AF.


2015 ◽  
Vol 114 (11) ◽  
pp. 1076-1084 ◽  
Author(s):  
Franziska Michalski ◽  
Luise Tittl ◽  
Sebastian Werth ◽  
Ulrike Hänsel ◽  
Sven Pannach ◽  
...  

SummaryAtrial fibrillation (AF) patients treated with well-controlled vitamin K antagonists (VKAs) may benefit less from non-vitamin K antagonist oral anticoagulants (NOACs) because they are supposed to be at low risk of thromboembolic and bleeding complications. However, little is known about the selection, management, and outcome of such “stable” VKA patients in current practice. We assessed characteristics, VKA persistence and 12 months' outcome of AF patients selected for VKA continuation. On March 1, 2013, the Dresden NOAC registry opened recruitment of patients continuing on VKA for sites that had been actively recruiting AF patients treated with NOACs in the prior 18 months. Patient characteristics were compared with those of NOAC patients from the same sites. Four hundred twenty-seven VKA patients had a significantly lower bleeding risk profile compared with 706 patients selected for NOAC treatment. For VKA, international normalised ratio time-in-therapeutic range before enrolment was 71% and increased to 75% during a mean follow-up of 15 months. Rates of stroke/transient ischaemic attack/systemic embolism were 1.3/100 patient-years (intention-to-treat) and 0.94/100 patient-years (as-treated). On-treatment rate of ISTH major bleeding was 4.15/100 patient-years (95% CI 2.60–6.29) with a case-fatality rate of 16.3% (all-cause mortality at day 90 after major bleeding). In conclusion, in daily care, AF patients selected for VKA therapy are healthier than those treated with NOAC, demonstrate a high quality of anticoagulant control and very low stroke rates. However, despite adequate patient selection and INR control, the risk of major VKA bleeding is unacceptably high and bleeding outcome is poor.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Arthur Shiyovich ◽  
Varda Shalev ◽  
Gabriel Chodick ◽  
Matanya Tirosh ◽  
Amos Katz ◽  
...  

Abstract Background Non-Vitamin K antagonist oral anticoagulants (NOACs) emerged as an alternative with comparable or superior efficacy and safety to vitamin K antagonists (VKAs) for stroke prevention in patients with non-valvular atrial fibrillation (AF). Objectives The aim of the current study was to investigate the patterns, predictors, timelines and temporal trends of shifting from VKAs to NOACs. Methods In this retrospective observational study, the computerized database of a large healthcare provider in Israel, Maccabi Healthcare Services, was searched to identify patients with AF for whom either a VKA or NOAC was prescribed between 2012 and 2015. Time from diagnosis to therapy initiation and to shifting between therapies was evaluated. Results Out of 6987 eligible AF incident patients, 2338 (33.4%) initiated treatment with a VKA and 2221 (31.7%) with a NOAC. In addition, 5259 prevalent patients were analyzed. During the study period, NOAC prescriptions proportion among the newly diagnosed cases increased from 32 to 68.4% (p for trend <  0.001). The median time from diagnosis to first dispensing was greater in NOAC than VKA and decreased among patients treated with NOAC during the study period (2012: 1.9 and 0.3 months, 2015: 0.7 and 0.2 months, respectively). During follow-up, 3737 (49%) patients (54.3% and 47.1% of the incident and prevalent cases, respectively), shifted from a VKA to a NOAC, after a median of 22 months and 39 months in the incident and prevalent cases, respectively, decreasing throughout the study period. Female gender, younger age, southern district, higher CHADS2 and CHA2DS2-VASC score, non-smoking, and treatment with antiplatelets were associated with a greater likelihood for therapy shift. Shifting from a NOAC to a VKA decreased over time from 8 to 4.5% in 2012 to 0.5% and 0.7% in 2015 in the incident and prevalent groups, p <  0.001 respectively. Conclusions Shifting from VKA to NOAC occurred in 50% of the cases, more frequently among incident cases, and younger patients with greater stroke risk. Shifting from a NOAC to a VKA was much less frequent, yet it occurred more often in incident cases and decreased over time. A socially and economically sensitive program to optimize the initiation of OAC therapy upon diagnosis is warranted.


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