Non-vitamin K antagonist oral anticoagulants (NOACs): clinical evidence and therapeutic considerations

Left Atrial Appendage Closure: What the Evidence Does and Does Not Reveal-A View from the Outside

This review summarizes the evidence for left atrial appendage closure (LAAC) as an alternative to oral anticoagulation (OAC) for stroke prevention in atrial fibrillation. LAAC reduces hemorrhagic stroke and mortality versus warfarin, but is inferior for ischemic stroke reduction based on randomized data. Whilst a feasible treatment in OAC-ineligible patients, questions remain over procedural safety, and the improvement in complications observed in nonrandomized registries is uncorroborated by contemporary randomized trials. Management of device-related thrombus and peridevice leak remain unclear, and robust randomized data versus direct OACs are required before recommendations can be made for widespread adoption in OAC-eligible populations.

Selection of Specific Aptamer against Rivaroxaban and Utilization for Label-Free Electrochemical Aptasensing Using Gold Nanoparticles: First Announcement and Application for Clinical Sample Analysis

For the first time, a novel aptamer was designed and utilized for the selective detection of rivaroxaban (RIV) using the integration of bioinformatics with biosensing technology. The selected aptamer with the sequence 5'-TAG GGA AGA GAA GGA CAT ATG ATG ACT CAC AAC TGG ACG AAC GTA CTT ATC CCC CCC AAT CAC TAG TGA ATT-3' displayed a high binding affinity to RIV and had an efficient ability to discriminate RIV from similar molecular structures. A novel label-free electrochemical aptasensor was designed and fabricated through the conjugation of a thiolated aptamer with Au nanoparticles (Au-NPs). Then, the aptasensor was successfully applied for the quantitative determination of RIV in human plasma and exhaled breath condensate (EBC) samples with limits of detection (LODs) of 14.08 and 6.03 nM, respectively. These valuable results provide ample evidence of the green electrogeneration of AuNPs on the surface of electrodes and their interaction with loaded aptamers (based on Au-S binding) towards the sensitive and selective monitoring of RIV in human plasma and EBC samples. This bio-assay is an alternative approach for the clinical analysis of RIV and has improved specificity and affinity. As far as we know, this is the first time that an electrochemical aptasensor has been verified for the recognition of RIV and that allows for the easy, fast, and precise screening of RIV in biological samples.

Expert Opinion on the Use of Novel Oral Anticoagulants for Stroke Prevention in Non-valvular Atrial Fibrillation for the Primary Care Setting in India: A Literature Review

Atrial fibrillation (AF), the most prevalent cardiac arrhythmia encountered in clinical practice, is linked with substantial morbidity and mortality due to accompanying risk of stroke and thromboembolism. Patients with AF are at a five-fold higher risk of suffering from a stroke. Anticoagulation therapy, with either vitamin K antagonists or novel oral anticoagulants (NOACs), is a standard approach to reduce the risk. Consultant physicians (CPs) in India are the primary point of contact for the majority of patients before they approach a specialist. The CPs may face challenges in screening and diagnosing AF patients. The apprehensions associated with managing AF patients with anticoagulants, further add to the challenges of a CP. This review aimed to identify the key decision points for the CPs to diagnose AF and initiate anticoagulation in patients with non-valvular AF (NVAF) and bring to the table a simplified recommendation supported by expert opinion and guidelines for stroke prevention in NVAF patients.

Left Atrial Appendage Closure: What the Evidence Does and Does Not Reveal-A View from the Outside

This review summarizes the evidence for left atrial appendage closure (LAAC) as an alternative to oral anticoagulation (OAC) for stroke prevention in atrial fibrillation. LAAC reduces hemorrhagic stroke and mortality versus warfarin, but is inferior for ischemic stroke reduction based on randomized data. Whilst a feasible treatment in OAC-ineligible patients, questions remain over procedural safety, and the improvement in complications observed in nonrandomized registries is uncorroborated by contemporary randomized trials. Management of device-related thrombus and peridevice leak remain unclear, and robust randomized data versus direct OACs are required before recommendations can be made for widespread adoption in OAC-eligible populations.

Direct Oral Anticoagulants: From Randomized Clinical Trials to Real-World Clinical Practice

Direct oral anticoagulants (DOACs) are a more manageable alternative than vitamin K antagonists (VKAs) to prevent stroke in patients with nonvalvular atrial fibrillation and to prevent and treat venous thromboembolism. Despite their widespread use in clinical practice, there are still some unresolved issues on optimizing their use in particular clinical settings. Herein, we reviewed the current clinical evidence on uses of DOACs from pharmacology and clinical indications to safety and practical issues such as drugs and food interactions. Dabigatran is the DOAC most affected by interactions with drugs and food, although all DOACs demonstrate a favorable pharmacokinetic profile. Management issues associated with perioperative procedures, bleeding treatment, and special populations (pregnancy, renal and hepatic impairment, elderly, and oncologic patients) have been discussed. Literature evidence shows that DOACs are at least as effective as VKAs, with a favorable safety profile; data are particularly encouraging in using low doses of edoxaban in elderly patients, and edoxaban and rivaroxaban in the treatment of venous thromboembolism in oncologic patients. In the next year, DOAC clinical indications are likely to be further extended.

Adverse drug reactions with oral anticoagulants: data from sicilian spontaneous reporting system database

OBJECTIVE

Direct oral anticoagulants (DOACs) were developed to avoid the limitations of vitamin K antagonists (VKAs). DOACs are associated with a greater incidence of gastrointestinal bleeding and a smaller number of intracranial haemorrhages than VKAs. Therefore, it is important to deepen our knowledge of their safety profiles. The aim of this study was thus to analyse adverse drug reaction (ADR) reports on DOACs and VKAs using the Sicilian Spontaneous Reporting System (SRS) database.

METHODS

All ADR reports with DOACs and VKAs as suspected drugs that were entered into the Sicilian SRS database during the period 2001-2019 were selected. In detail, all reports with the following single active substances were included: dabigatran etexilate, rivaroxaban, apixaban and edoxaban; acenocoumarol and warfarin were included as a comparator group. Descriptive statistical methodology was used to evaluate characteristics of the reported cases with a case-by-case assessment.

RESULTS AND DISCUSSION

Out of 521 reports related to anticoagulants, 444 (85.2%) and 77 (14.8%) involved DOACs and VKAs, respectively. DOAC-related reports were mainly of gastrointestinal disorders. In contrast, VKAs were mostly associated with blood and lymphatic system disorders, injury, investigations and vascular disorders. Many more cases of ADRs in the form of gastrointestinal disorders concerned dabigatran etexilate (n = 179, 73.7%) than the other DOACs, while ADRs in the form of blood disorders were mainly associated with acenocoumarol (n = 27, 57.4%). The most commonly reported Preferred Terms for DOACs were dyspepsia (n = 89, 17.1%), upper abdominal pain (n = 41, 9.2%) and pruritus (n = 26, 5.8%), whereas for VKAs, they were anaemia (n = 21, 27.3%) and hypocoagulable state (n = 18, 3.5%). Potentially interacting concomitant medications particularly included antithrombotic agents (n = 19, 4.3%) for DOACs and proton-pump inhibitors (PPIs) (n = 37, 48.1%) and antithrombotic agents (n = 13, 16.9%) for VKAs.

CONCLUSION

The ADRs most commonly associated with DOACs, especially dabigatran, were gastrointestinal disorders, particularly gastrointestinal bleeding. Our study also highlights the potential role of drug-drug interactions in the ADRs. The cases of gastrointestinal bleeding highlight the need for careful prescribing of DOACs and use of potentially interacting concomitant drugs.

Analysis of the Introduction in Clinical Practice of New Oral Anticoagulants in Local Health Agency BT: Translation of the Clinical Trial Data to a Local Health Care Area

The commercial release of the New Oral Anticoagulants (NOACs) has been the most significant change in anticoagulant therapy in recent years. The work aimed to evaluate the economic and health impact for the Local Health Agency Barletta-Andria-Trani (BT). Through the Regional Information System data about naïve patients on NOAC treatment and patients on anti-vitamin-k (VKA), treatments were extrapolated. We assessed therapeutic continuity, pharmaceutical expenditure, hospitalizations, and deaths in 2017 and 2018. Therapeutic continuity was similar in the two groups. The number and the average cost of hospitalizations for a patient treated with VKAs were almost constant, while those of patients treated with NOACs decreased. The treatment of adult-aged naïve patients with NOACs, compared to VKAs therapy, involves an increase in expenditure of about 100€ for a patient, but the reduced hospitalizations could generate, in the long term, saving for the Health System. Clinical data, according to the Real-World Data, confirmed the safety and effectiveness of these drugs. However, attention to the special population is necessary to improve the safety and effectiveness of NOACs. Innovative formulations for pediatric patients are being developed. The challenge for Health Systems is the appropriate use of available resources through health interventions with transversal competences.

What are the Characteristics of Patients Experiencing Adverse Drug Reactions to Oral Anticogulants and How Can Such Reactions be Prevented?

INTRODUCTION

Oral anticoagulants, including vitamin K inhibitors (VKAs) and direct anticoagulants (DOACs) are important for preventing and treating thromboembolic diseases. However, they are not recommended for use in all patients due to negative side effects and adverse drug reactions (ADRs). Currently, there is a paucity of information about their use in real life. Therefore, the aim of this pilot study is to report on the rate of serious ADRs in oral anticoagulant users, determine patient characteristics associated with increased risk of ADRs, and identify possible management strategies for reducing risk of ADRs within a hospital setting.

METHODS

Patients admitted to the Internal Medicine Department of the Vimercate Hospital were recruited between November 1, 2015 and October 31, 2016. All patients reporting an ADR associated with anticoagulant use were selected. Demographic, clinical, and observational data were extracted from electronic hospital records, in particular, by the hospital discharge letters and other clinical records. The main outcome of the study was to evaluate the incidence of anticoagulants serious adverse drug reactions conditioning hospital admission, the percentage of preventable reactions, and the determinants of those.

RESULTS AND DISCUSSION

Of the 2,064 admissions, 102 (4.9%) eligible patients were identified. Age ranged from 60-95 years (mean = 81.9, standard deviation = 6,59) and 47.1% (n=48) were female. Of the 102 cases, 68 used VKAs and 34 used DOACs. The most common admission diagnosis was heart failure following anemia or hemorrhage (56 cases), followed by acute hemorrhage (with or without anemia; 29 cases), and anemia not associated with evident hemorrhage (17cases). The majority of VKA users (n=65, 95.6%) had a high risk of major bleeding. ADRs were found to be preventable in 96% of VKA users and 68% of DOACs users.

CONCLUSION

This study highlights the large percentage of ADRs from oral anticoagulants that can be avoided with more careful patient management. Periodic check-up of cardiac and renal function, as well as blood count, may be useful for reducing the risk of ADRs, especially in older DOACs users. Further research is needed to get new data to improve the patients monitoring system.

Simultaneous determination of Rivaroxaban and TAK-438 in rat plasma by LC-MS/MS: application to pharmacokinetic interaction study

Aim: A sensitive and reliable LC-MS/MS method has been established and validated to the quantitation of rivaroxaban (RIV) and TAK-438 in rat plasma using carbamazepine as internal standard. Results: The procedure of method validation was conducted according to the guidelines of EMA and US FDA. At the same time, the method was applied to pharmacokinetic interactions study between RIV and TAK-438 for the first time. When RIV and TAK-438 co-administration to rats, main pharmacokinetic parameters of TAK-438 like AUC_(0-t), AUC_(0-∞) and C_max had statistically significant increase. The main pharmacokinetic parameters of RIV have no statistically significant difference (p > 0.05) when co-administered except for t_1/2 (p < 0.01). Conclusion: The results indicated that drug-drug interactions occurred between RIV and TAK-438 when co-administered to rats.

Non-vitamin K antagonist oral anticoagulants and sport

Physical activity is worldwide recommended for its benefits on cardiovascular system. There is an increasing number of people of all ages that approach sport activity both as leisure time physical activity and as competitive sport. It is always more frequent the request even from older subjects and cardiac patients to be allowed to practice physical activity. Some problems could arise when these subjects present or develop pathologic conditions that require specific pharmacological treatment, in particular an anticoagulation therapy. This review focalizes on the management of oral anticoagulant therapy (OAT) in patients practicing sport activity, especially due to atrial fibrillation and deep vein thrombosis, which represent two highly prevalent conditions, particularly with increasing age. Official recommendations in this field may appear limiting for patients, forbidding in the majority of cases sports at risk of trauma and consequent bleeding. These recommendations still resent the heritage of the "traditional" management of OAT, mainly represented by vitamin-K antagonists (VKAs). The non-vitamin K antagonist oral anticoagulants, with their more favorable pharmacokinetic-pharmacodynamic profile compare to VKAs, may now represent an opportunity to modify the approach to sport activity in patients with an indication to OAT. This review of the literature deals with possible strategies to overcome the present limitations for OAT subjects willing to pursue a healthy lifestyle, that include sport activity, minimizing at the same time their risk of bleeding.

Comparative safety and effectiveness of rivaroxaban versus VKAs in patients with venous thromboembolism

The approval of rivaroxaban has changed the landscape of treatment of venous thromboembolism (VTE). Little is known about the effect of rivaroxaban compared with vitamin K antagonists (VKA), when used in the everyday clinical practice. The aim of this study was to investigate the safety and effectiveness of rivaroxaban compared with VKAs among patients with VTE, using the Danish nationwide registries. All patients diagnosed with VTE and treated with either rivaroxaban or VKAs between 2013 and 2015 were included. A total of 12,318 patients were diagnosed with VTE and treated with VKAs [n=6,907] or rivaroxaban [n=5,411.]. Combined Cox regression analyses showed that the standardised absolute six-month risk of recurrent VTE was 3.03 % [95 % CI: 2.57 % to 3.48 %] in the rivaroxaban group and 3.13 % [95 % CI: 2.70 % to 3.56 %] in the VKA group (absolute risk difference of –0.11 % [95 % CI: –0.76 % to 0.54 %]). The standardised absolute six-months risk of bleeding was 2.28 % [95 % CI: 1.87 % to 2.67 %] for patients in the rivaroxaban group and 2.10 % [95 % CI: 1.78 % to 2.43 %] in the VKA group (absolute risk difference of 0.18 % [95 % CI: –0.34 % to 0.67]). In conclusion, rivaroxaban was associated with similar risk of recurrent VTE and bleeding compared with VKA.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Reversing Dabigatran Anticoagulation with Prothrombin Complex Concentrate versus Idarucizumab as Part of Multimodal Hemostatic Intervention in an Animal Model of Polytrauma

BACKGROUND

Although idarucizumab is the preferred treatment for urgent dabigatran reversal, it is not always available. Prothrombin complex concentrate (PCC) may be an alternative and, with bleeding in trauma, additional hemostatic therapy may be required. The authors investigated multimodal treatment in a preclinical polytrauma model.

METHODS

Dabigatran etexilate (30 mg/kg twice daily) was given orally to 45 male pigs for 3 days. On day 4, animals received a dabigatran infusion before blunt liver injury and bilateral femur fractures. After injury, animals were randomized 1:1:1:1:1 to receive placebo (control), tranexamic acid (TXA; 20 mg/kg) plus human fibrinogen concentrate (FCH; 80 mg/kg) (TXA-FCH group), PCC (25 U/kg or 50 U/kg) plus TXA plus FCH (PCC25 and PCC50 groups), or 60 mg/kg idarucizumab (IDA) plus TXA plus FCH (IDA group). Animals were monitored for 240 min after trauma, or until death.

RESULTS

The degree of injury was similar in all animals before intervention. Control and TXA-FCH animals had the highest total postinjury blood loss (3,652 ± 601 and 3,497 ± 418 ml) and 100% mortality (mean survival time 96 and 109 min). Blood loss was significantly lower in the PCC50 (1,367 ± 273 ml) and IDA (986 ± 144 ml) groups, with 100% survival. Thrombin-antithrombin levels and thrombin generation were significantly elevated in the PCC50 group.

CONCLUSIONS

Idarucizumab may be considered the optimal treatment for emergency reversal of dabigatran anticoagulation. However, this study suggests that PCC may be similarly effective as idarucizumab and could therefore be valuable when idarucizumab is unavailable. (Anesthesiology 2017; 127:852-61).

First Reported Case of Hemopericardium Related to Dabigatran Use Reversed by New Antidote Idarucizumab

Dabigatran, the first novel oral anticoagulant (NOAC) with a reversal agent, heralded a paradigm shift in the treatment of nonvalvular atrial fibrillation. The potential for life-threatening hemorrhagic events with the use of NOACs has been highly debated since the effectiveness of reversal agents such as idarucizumab is based primarily on pharmacologic data. It is known that cancer patients are at an increased risk of bleeding with anticoagulation, though specific studies demonstrating the risks or efficacy of NOACs in this population are lacking. We provide the first report of hemopericardium resulting in multiorgan failure related to dabigatran use that was successfully reversed by idarucizumab in a man with prostate cancer on chemotherapy.

A practical approach to the new oral anticoagulants used for stroke prevention in patients with atrial fibrillation

This review evaluates the research undertaken in the last six years on the use of new oral anticoagulants for stroke prevention in atrial fibrillation and provides evidence-based answers to common clinical questions. Two types of new oral anticoagulants - direct thrombin (IIa) inhibitors, and Xa inhibitors - are currently available. These drugs have similar pharmacokinetics and pharmacodynamics. They are more predictable than, though in many respects comparable to, warfarin. They do not require frequent laboratory tests, nor do they have a narrow therapeutic window. When a patient requires surgery, new oral anticoagulants are easier to manage than warfarin due to their short half-lives. Short half-lives reduce the length of bleeding events. Information obtained from risk calculators such as CHA2DS2-VASc and HAS-BLED should be considered before prescribing. New oral anticoagulants are useful in every day clinical practice, but there are complex factors that should be considered in each patient before prescribing to implement the best practice and achieve the best results.

Antibiofilm effect of warfarin on biofilm formation of Escherichia coli promoted by antimicrobial treatment

Enhancement of microbial biofilm formation by low antimicrobial doses is a critical problem in the medical field. The objective of this study was to propose a new drug candidate against the biofilm formation promoted by subinhibitory dose of antimicrobials. To determine the effect on biofilm formation of Escherichia coli, a subinhibitory concentration of lactoferrin (LF), a milk protein involved in a broad range of biological properties including antimicrobial action, or ampicillin (AMP), a typical antibiotic, was added to an E. coli cell culture in a 96-well microtiter plate. On the other hand, warfarin (WARF), an oral anticoagulant, or polymyxin B (PMB), a strong antibiotic for biofilm treatment, was added as an antagonist against the biofilm promoted by LF or AMP. The amount of biofilm formed at 100μg/mL LF in lysogeny broth medium was four times higher than in the absence of LF. Meanwhile, it was found that WARF suppressed the LF-promoted biofilm formation to a level comparable with the LF-free condition. WARF worked in a similar manner to PMB, which is known as an antibiofilm agent. Furthermore, WARF could also suppress the biofilm promoted by AMP. In conclusion, this study suggests that WARF can work as an antibiofilm agent against the biofilm formation promoted by subinhibitory dose of antimicrobials.

The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) : Exploring the changes in anticoagulant practice in patients with non-valvular atrial fibrillation in the Netherlands

There are over 385,000 cases of atrial fibrillation (AF) in the Netherlands, with over 45,000 new cases each year. Among other things, AF patients are at high risk of stroke. Patients are often prescribed oral anticoagulation, such as vitamin K antagonists (VKA), to mitigate these risks. A recently introduced class of oral anticoagulants, non-vitamin K antagonists (NOAC), is quickly gaining currency in global clinical practice. This study provides insight into the changes these new drugs will bring about in Dutch clinical practice.

GARFIELD-AF is a large-scale observational AF patient registry initiated in 2009 to track the evolution of global anticoagulation practice, and to study the impact of NOAC therapy in AF in particular. The registry includes a wide array of baseline characteristics and has a particular focus on: (1) bleeding and thromboembolic events; (2) international normalised ratio fluctuations; and (3) therapy compliance and persistence patterns. The results in this paper provide the baseline characteristics of the first cohorts of Dutch participants in this registry and discuss some of the consequences of the changes in anticoagulation practice.

Although VKA therapy remains overwhelmingly favoured by Dutch practitioners, NOACs are clearly gaining in popularity. Between 2011 and 2014, NOACs constituted an increasingly large proportion of prescriptions for oral anticoagulants.

The insights provided by the GARFIELD-AF registry can be used by healthcare systems to inform better budgetary strategies, by practitioners to better tailor treatment pathways to patients, and finally to promote awareness of the various available treatment options and their associated risks and benefits for patients.

Potential Effect of Substituting Estimated Glomerular Filtration Rate for Estimated Creatinine Clearance for Dosing of Direct Oral Anticoagulants

OBJECTIVES

To determine the potential effect of substituting glomerular filtration rate (GFR) estimates for renal clearance estimated using the Cockcroft-Gault method (CrCL-CG) to calculate direct oral anticoagulant (DOAC) dosing.

DESIGN

Simulation and retrospective data analysis.

SETTING

Community, academic institution, nursing home.

PARTICIPANTS

Noninstitutionalized individuals aged 19 to 80 from the National Health and Nutrition Examination Survey (NHANES) (2011/12) (n = 4,687) and medically stable research participants aged 25 to 105 (n = 208).

MEASUREMENTS

Age, height, weight, sex, race, serum creatinine, CrCL-CG, and GFR (according to the Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration equations). Outcome measures were dosing errors if GFR were to be substituted for CrCL-CG.

RESULTS

Renal clearance estimates according to all methods were highly correlated (P < .001), although at lower clearances, substitution of GFR estimates for CrCL-CG resulted in failure to recognize needs for dose reductions of rivaroxaban or edoxaban in 28% of NHANES subjects and 47% to 56% of research subjects. At a CrCL-CG of less than 30 mL/min, GFR estimates missed indicated dosage reductions for dabigatran in 18% to 21% of NHANES subjects and 57% to 86% of research subjects. Age and weight contributed to differences between renal clearance estimates (P < .001), but correction of GFR for body surface area (BSA) did not reduce dosing errors. At a CrCL-CG greater than 95 mL/min, edoxaban is not recommended, and GFR esimates misclassified 24% of NHANES and 39% of research subjects. Correction for BSA reduced misclassification to 7% for NHANES and 14% in research subjects.

CONCLUSION

Substitution of GFR estimates for estimated CrCl can lead to failure to recognize indications for reducing DOAC dose and potentially higher bleeding rates than in randomized trials.

Cost-effectiveness of edoxaban versus rivaroxaban for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) in the US

BACKGROUND

Understanding the value of new anticoagulation therapies compared with existing therapies is of paramount importance in today's cost-conscious and efficiency-driven health care environment. Edoxaban and rivaroxaban for stroke prevention in nonvalvular atrial fibrillation (NVAF) patients with CHADS2 scores ≥2 have been evaluated in pivotal trials versus warfarin. The relative value of edoxaban versus rivaroxaban would be of interest to health care stakeholders and patients who prefer a once-daily treatment option for long-term stroke prevention in NVAF.

OBJECTIVE

To evaluate the relative cost-effectiveness of two once-daily regimens of novel oral anticoagulation therapy - edoxaban (60 mg/30 mg dose-reduced) versus rivaroxaban (20 mg/15 mg dose-reduced) - for stroke prevention in NVAF patients from a US health-plan perspective.

MATERIALS AND METHODS

A Markov model simulated lifetime risk and treatment of stroke, systemic embolism, major bleeding, clinically relevant nonmajor bleeding, myocardial infarction, and death in NVAF patients treated with edoxaban or rivaroxaban. Efficacy and safety data were derived from a network meta-analysis that utilized data from patients enrolled in ENGAGE AF-TIMI 48 and ROCKET-AF. Health care cost and utility data were obtained from published sources. Incremental cost-effectiveness ratios of $150,000 per quality-adjusted life year (QALY) gained were used as thresholds for "highly cost-effective", "cost-effective", and "not cost-effective" treatment options, respectively, as per American Heart Association/American College of Cardiology guidelines.

RESULTS

Edoxaban was dominant relative to rivaroxaban, such that it was associated with lower total health care costs and better effectiveness in terms of QALYs in the base-case analysis. Results were supported by probabilistic sensitivity analyses that showed edoxaban as either dominant or a highly cost-effective alternative (incremental cost-effectiveness ratio <$50,000) to rivaroxaban in 88.4% of 10,000 simulations.

CONCLUSION

Results of this study showed that the once-daily edoxaban (60 mg/30 mg dose-reduced) regimen is a cost-saving or highly cost-effective treatment relative to rivaroxaban (20 mg/15 mg dose-reduced) for stroke prevention in NVAF patients with CHADS2 ≥2.

Novel Oral Anticoagulants for Venous Thromboembolism with Special Emphasis on Risk of Hemorrhagic Complications and Reversal Agents

Warfarin was the only oral anticoagulant available for the treatment of venous thromboembolism for about half a century until the recent approval of novel oral agents dabigatran, rivoraxaban and apixaban. This presents new classes of medications less cumbersome to use. They do not require frequent laboratory monitoring or have nurmerous drug interactions. On the other hand it also poses a challenge to the physicians deciding which agent to use in specific patient populations, how to predict the bleeding risk compared to warfarin and between the different novel agents and how to manage bleeding with relatively recent discovery of few potential antidotes. This review summarizes the major trials that led to the approval of these agents and their exclusion criteria helping physicians understand which patient types might not benefit from these agents. It provides clinical pearls invaluable in everyday practice such as transitioning between traditional and novel anticoagulants, dose adjustments for high risk populations, drug interactions and cost analysis. Futhermore, the review provides direct comparisons with warfarin and indirect comparisons among the novel agents in terms of efficacy and bleeding risk narrating the numbers of patients with intracranial, gastrointestinal and fatal hemorrhages in each of the major trials. We hope that this review will help the physicians inform their patients about the benefits and risks of these agents and enable them to make an informed selection of the most appropriate anticoagulant.