Pharmacological properties of betrixaban

Management of patients with proximal femur fractures under DOACs

PURPOSE

In the past, preinjury direct oral anticoagulant (DOAC) intake has led to delays in time to surgery (TTS) in patients with proximal femur fractures and delays in surgery have been associated with impaired outcomes. Although healthcare institutions/federal committees have set rules for treatment within 24 h of injury, comprehensive guidelines for the perioperative management of these patients, in particular when on preinjury DOACs, are still lacking. This contribution aims to summarize the current evidence on the safe time window for surgery in patients with proximal femur fractures on preinjury DOACs and to outline therapeutic options if emergency DOAC reversal becomes necessary.

METHODS

Narrative review based upon selective review of the pertinent literature.

RESULTS

For the majority of patients with proximal femur fractures and on preinjury DOACs, early surgery appears safe as soon as medical clearance has been obtained. There may be an increase in the need for blood products but with data not yet conclusive. Work-up including assessment of remaining anticoagulant activity and potential reversal should be restricted to patients at risk for bleeding complications, in particular in the presence of renal/hepatic impairment. Methodology for rapid assessment of DOACs including quantitative/qualitative concentration levels is work in progress. In the case of bleeding, rapidly acting reversal agents are available.

CONCLUSION

Preinjury DOAC use should not routinely delay surgery in patients with proximal femur fractures.

An Update on Betrixaban, The Challenging Anticoagulant Agent for Extended Venous Thromboembolism Prophylaxis

ABSTRACT

Venous thromboembolism (VTE) is a prevalent yet preventable cause of death, particularly among hospitalized patients. Studies have shown that the risk of VTE remains high for up to 6 months after discharge, highlighting the need for extended thromboprophylaxis as a viable treatment approach. Despite the availability of several anticoagulant drugs such as vitamin K antagonists, heparinoids, rivaroxaban, apixaban, edoxaban, and dabigatran, none of them has received approval from the US Food and Drug Administration for long-term thromboprophylaxis. However, an emerging factor Xa inhibitor called betrixaban has shown promising results in Phase II and phase III trials, positioning itself as the first and only US Food and Drug Administration-approved anticoagulant for extended thromboprophylaxis in hospitalized patients after discharge. Betrixaban offers distinct pharmacological characteristics, including a long half-life, low renal excretion, and unique hepatic metabolism, making it an attractive option for various theoretical uses. Numerous articles have been published discussing the safety and efficacy of betrixaban, all of which have emphasized its usefulness and practicality. However, there has been limited discussion regarding its weaknesses and areas of ambiguity. Therefore, this article aimed to explore the challenges faced during the approval process of betrixaban and provide a comprehensive review of the literature on its advantages and disadvantages as a long-term prophylaxis approach for VTE. Furthermore, we aim to identify the ambiguous points that require further investigation in future studies.

Anticoagulation in chronic kidney disease: current status and future perspectives

Chronic kidney disease (CKD) is being diagnosed increasingly worldwide. It is often identified in individuals with comorbidities, which may increase the already heightened risk of thrombosis and hemorrhage associated with CKD. Oral anticoagulation is an effective means of reducing rates of ischemic stroke and systemic embolism in patients with atrial fibrillation and minimizes the morbidity and mortality caused by venous thromboembolic disease. Despite the proven benefits in the majority of patients, these have not been so clearly realized in patients with CKD due to the precarious balance between bleeding and thromboembolic complications. In this review, the current status of anticoagulant utilization in CKD is examined, and some practical recommendations are put forward to assist in the decision-making process of safely anticoagulating patients with CKD diagnosed with atrial fibrillation and venous thromboembolism.

Targeting SARS-CoV-2 Main Protease: A Successful Story Guided by an In Silico Drug Repurposing Approach

The SARS-CoV-2 main protease (Mpro) is a crucial enzyme for viral replication and has been considered an attractive drug target for the treatment of COVID-19. In this study, virtual screening techniques and in vitro assays were combined to identify novel Mpro inhibitors starting from around 8000 FDA-approved drugs. The docking analysis highlighted 17 promising best hits, biologically characterized in terms of their Mpro inhibitory activity. Among them, 7 cephalosporins and the oral anticoagulant betrixaban were able to block the enzyme activity in the micromolar range with no cytotoxic effect at the highest concentration tested. After the evaluation of the degree of conservation of Mpro residues involved in the binding with the studied ligands, the ligands' activity on SARS-CoV-2 replication was assessed. The ability of betrixaban to affect SARS-CoV-2 replication associated to its antithrombotic effect could pave the way for its possible use in the treatment of hospitalized COVID-19 patients.

Current and emerging drug strategies for the prevention of venous thromboembolism in acutely ill medical inpatients

INTRODUCTION

Venous thromboembolism (VTE) is a common complication in patients hospitalized for acute medical illnesses. Therefore, medical inpatients require a careful VTE and bleeding risk assessment to drive optimal strategies for VTE prevention. Low molecular weight heparin and fondaparinux have long been used for inhospital prophylaxis for patients at increased risk of VTE. The selection of patients who require post-discharge prophylaxis, and the role of direct oral anticoagulants remain debated. New molecules currently under development may contribute to improve the risk benefit of VTE prevention in this setting.

AREAS COVERED

This text summarizes the evidence on approved treatments and on other drugs for the prevention of VTE in acutely ill medical patients. The main focus is on their pharmacological proprieties, clinical efficacy and safety, and the current license approved by the FDA (Food and Drug Administration) and EMA (European Medicines Agency), giving the readers a way to compare available drugs to date. The trials presented consider both inhospital and extended prophylaxis.

EXPERT OPINION

Thanks to the potentially favorable safety profile, factor XI inhibitors may play a role in the prevention of VTE in this setting. The expert opinion section discusses pharmacological properties, prophylaxis trials, and potential clinical applications of this novel class of drugs.

Comparison of the Direct Oral Anticoagulants and Warfarin in Patients With Atrial Fibrillation and Valvular Heart Disease: Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Direct oral anticoagulants (DOACS) are approved for use in non-valvular atrial fibrillation (AF). This systematic review and meta-analysis aimed to evaluate the efficacy and safety of DOACs vs. warfarin and update the evidence for treatment of AF and valvular heart disease (VHD).

Methods: We identified randomized clinical trials (RCTs) and post-hoc analyses comparing the use of DOACS and Warfarin in AF and VHD, including biological and mechanical heart valves (MHV), updating from 2010 to 2020. Through systematic review and meta-analysis, by using the “Rev Man” program 5.3, the primary effectiveness endpoints were stroke and systemic embolism (SE). The primary safety outcome was major bleeding, while the secondary outcome included intracranial hemorrhage. We performed prespecified subgroup analyses. Data were analyzed by risk ratio (RR) and 95% confidence interval (CI) and the I-square (I²) statistic as a quantitative measure of inconsistency. Risk of bias and methodological quality assessment of included trials was evaluated with the modified Cochrane risk-of-bias tool.

Results: We screened 326 articles and included 8 RCTs (n = 14.902). DOACs significantly reduced the risk of stroke/SE (RR 0.80, 95% CI: 0.68–0.94; P = 0.008; moderate quality evidence; I² = 2%) and intracranial hemorrhage (RR 0.40, 95% CI: 0.24–0.66; P = 0.0004; I² = 49%) with a similar risk of major bleeding (RR 0.83, 95% CI: 0.56–1.24; P = 0.36; I² = 88%) compared to Warfarin.

Conclusions: In this update, DOACs remained with similar efficacy and safety compared to warfarin in thromboprophylaxis for AF and VHD.

Updates on Anticoagulation and Laboratory Tools for Therapy Monitoring of Heparin, Vitamin K Antagonists and Direct Oral Anticoagulants

Anticoagulant drugs have been used to prevent and treat thrombosis. However, they are associated with risk of hemorrhage. Therefore, prior to their clinical use, it is important to assess the risk of bleeding and thrombosis. In case of older anticoagulant drugs like heparin and warfarin, dose adjustment is required owing to narrow therapeutic ranges. The established monitoring methods for heparin and warfarin are activated partial thromboplastin time (APTT)/anti-Xa assay and prothrombin time – international normalized ratio (PT-INR), respectively. Since 2008, new generation anticoagulant drugs, called direct oral anticoagulants (DOACs), have been widely prescribed to prevent and treat several thromboembolic diseases. Although the use of DOACs without routine monitoring and frequent dose adjustment has been shown to be safe and effective, there may be clinical circumstances in specific patients when measurement of the anticoagulant effects of DOACs is required. Recently, anticoagulation therapy has received attention when treating patients with coronavirus disease 2019 (COVID-19). In this review, we discuss the mechanisms of anticoagulant drugs—heparin, warfarin, and DOACs and describe the methods used for the measurement of their effects. In addition, we discuss the latest findings on thrombosis mechanism in patients with COVID-19 with respect to biological chemistry.

Expert Consensus Decision Pathway of the American College of Cardiology on Management of Bleeding in Patients With Oral Anticoagulants: A Review of the 2020 Update for Perioperative Physicians

The use and evolution of oral anticoagulation therapies continue to advance for multiple reasons, including a growing segment of older patients with associated chronic prothrombotic illnesses including cardiovascular, pulmonary, hematologic and oncologic conditions. Correlated to this increased use of oral anticoagulants is bleeding complications associated with their use. Based on these trends, it is expected that perioperative physicians will be facing more and more of these patients requiring scheduled, urgent or emergent surgical procedures During May 2020, the American College of Cardiology updated its Expert Consensus Decision Pathway devoted to the approach of bleeding in patients on oral anticoagulants. This updated version emphasized the expanding role of the direct-acting oral anticoagulants in other conditions beyond nonvalvular atrial fibrillation, such as venous thromboembolism. Several details discussed within this most recent update are pertinent to perioperative physicians, who frequently deal with bleeding in the setting of anticoagulation. The purpose of this narrative review is to highlight and expand on these salient points because they relate to perioperative management.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

This comprehensive review of the 2019 restorative dental literature is offered to inform busy dentists regarding remarkable publications and noteworthy progress made in the profession. Developed by the Scientific Investigation Committee of the American Academy of Restorative Dentistry, each author brings discipline-specific expertise to 1 of 8 sections of the report: (1) prosthodontics; (2) periodontics, alveolar bone, and peri-implant tissues; (3) implant dentistry; (4) dental materials and therapeutics; (5) occlusion and temporomandibular disorders; (6) sleep-related breathing disorders; (7) oral medicine and oral and maxillofacial surgery; and (8) dental caries and cariology. The report targets important information likely to influence day-to-day dental treatment decisions. Each review is not intended to stand alone but to update interested readers so that they may visit source material when greater detail is desired. As the profession moves toward evidence-based clinical decision-making, an incredible volume of potentially valuable dental literature continues to increase. It is the intention of this review and its authors to provide assistance in negotiating the extensive dental literature published in 2019. It is our hope that readers find this work useful in the clinical management of dental patients.

Warden B. Direct Oral Anticoagulant Use: A Practical Guide to Common Clinical Challenges

Direct oral anticoagulants ( DOAC s) have quickly become attractive alternatives to the long‐standing standard of care in anticoagulation, vitamin K antagonist. DOAC s are indicated for prevention and treatment of several cardiovascular conditions. Since the first approval in 2010, DOAC s have emerged as leading therapeutic alternatives that provide both clinicians and patients with more effective, safe, and convenient treatment options in thromboembolic settings. With the expanding role of DOAC s, clinicians are faced with increasingly complex decisions relating to appropriate agent, duration of treatment, and use in special populations. This review will provide an overview of DOAC s and act as a practical reference for clinicians to optimize DOAC use among common challenging scenarios. Topics addressed include (1) appropriate indications; (2) use in patients with specific comorbidities; (3) monitoring parameters; (4) transitioning between anticoagulant regimens; (5) major drug interactions; and (6) cost considerations.

Warden B. Direct Oral Anticoagulant Use: A Practical Guide to Common Clinical Challenges

Direct oral anticoagulants (DOACs) have quickly become attractive alternatives to the long-standing standard of care in anticoagulation, vitamin K antagonist. DOACs are indicated for prevention and treatment of several cardiovascular conditions. Since the first approval in 2010, DOACs have emerged as leading therapeutic alternatives that provide both clinicians and patients with more effective, safe, and convenient treatment options in thromboembolic settings. With the expanding role of DOACs, clinicians are faced with increasingly complex decisions relating to appropriate agent, duration of treatment, and use in special populations. This review will provide an overview of DOACs and act as a practical reference for clinicians to optimize DOAC use among common challenging scenarios. Topics addressed include (1) appropriate indications; (2) use in patients with specific comorbidities; (3) monitoring parameters; (4) transitioning between anticoagulant regimens; (5) major drug interactions; and (6) cost considerations.

Expedient Approach to the Synthesis of Betrixaban

A new scalable route to synthesize the factor Xa (FXa) inhibitor betrixaban is disclosed. The product is obtained in a seven-step reaction sequence (in five stages using two one-pot reactions) starting from easily accessible 4-(N,N-dimethylcarbamimidoyl)benzoate. Effective isolation of intermediates, use of cost-effective amide formation and 2-methyltetrahydrofuran as an effective reaction solvent as well as for extraction in three of the stages, are key features. The strategy provides the desired product in 38% overall yield with high purity (>98%).

A Review on the Use of Reversal Agents of Direct Oral Anticogulant Drugs in Case of Gastrointestinal Bleeding

BACKGROUND

Major bleeding is a life-threatening condition and a medical emergency with high mortality risk. It is often the complication of anticoagulant's intake. Anticoagulants are commonly used for the prevention and treatment of thrombotic events. The standard therapy with vitamin K antagonist (warfarin) has been frequently replaced by direct oral anticoagulants (DOACs). The latter agents (rivaroxaban, apixaban, edoxaban, dabigatran, and betrixaban) showed better efficacy and safety compared to standard warfarin treatment and they are recommended for the reduction of ischemic stroke. Literature data reported a high risk of gastrointestinal bleeding with DOACs, in particular with dabigatran and rivaroxaban. In case of life-threatening gastrointestinal bleeding, these patients could benefit from the use of reversal agents.

METHODS

We performed an electronic search on PUBMED of the literature concerning reversal agents for DOACs and gastrointestinal bleeding in the Emergency Department from 2004 to 2020.

AIM

This review summarizes the current evidence about three reversal agents idarucizumab, andexanet alfa and ciraparantag, and the use of the first two in the emergency setting in patients with active major bleeding or who need urgent surgery which physicians indicate for a better management approach in order to increase patient's safety.

CONCLUSION

Although these agents have been marketed for five years (idarucizumab) and two years (andexanet alfa) respectively, and despite guidelines considering antidotes as first-line agents in treating life-threatening hemorrhage when available, these antidotes seem to gain access very slowly in the clinical practice. Cost, logistical aspects and need for plasma level determination of DOAC for an accurate therapeutic use probably have an impact on this phenomenon.. An expert multidisciplinary bleeding team should be established so as to implement international guidelines based on local resources and organization.

Updates in periprocedural management of direct oral anticoagulants

PURPOSE OF REVIEW

As the prevalence of patients on antithrombotics is increasing, anesthesiologists must have a firm understanding of these medications and considerations for their periprocedural management. This review details up-to-date periprocedural management of direct oral anticoagulants (DOACs).

RECENT FINDINGS

DOACs have favorable pharmacokinetics including quick onset of action and short half-lives. Periprocedural management of DOACs relies heavily on drug half-life as well as procedural risk of bleeding. Other than a few exceptions, the American College of Cardiologists generally recommends complete clearance of oral anticoagulants prior to high-risk bleeding procedures and partial clearance prior to low-risk bleeding procedures. Procedures with little to no clinical risk of bleeding can be performed without any drug interruption or during trough levels. Exceptions to periprocedural DOAC management pertain to electrophysiology procedures.

SUMMARY

With the exception of no clinically relevant bleeding risk or certain electrophysiology procedures, DOACs should be discontinued periprocedurally in accordance with bleeding risks and drug's half-life. Bridging is generally not recommended for DOACs.

Assessing and Reversing the Effect of Direct Oral Anticoagulants on Coagulation

This article presents a focused review of the available tests to assess the effect of direct oral anticoagulants on coagulation and the use of reversal agents in the perioperative setting for practicing anesthesiologists.

Direct oral anticoagulants: A new chapter in anticoagulation therapy

Thromboembolic events are the leading cause of morbidity and mortality worldwide. From the second half of the 20th century, vitamin K antagonists (VKAs), warfarin and acenocoumarol, were the only anticoagulants taken orally. The major reform in anticoagulation therapy was made by the advent of direct oral anticoagulants (DOACs), about 10 years ago. Direct thrombin inhibitor (dabigatran) and direct inhibitors of factor Xa (rivaroxaban, apixaban, edoxaban, and betrixaban) have demonstrated favorable risk/benefit ratio. Compared to warfarin, DOACs are associated with a predictable pharmacokinetic profile, lower severe bleeding complications, particularly intracranial hemorrhages, and minimal drug interactions. Moreover, DOACs achieve a rapid onset of action and have shown comparable efficacy with warfarin and low molecular weight heparin (LMWH) in clinical trials. As a result, DOACs are now replacing VKAs and LMWH for many indications including stroke and systemic embolism prevention in nonvalvular atrial fibrillation, prevention, and treatment of venous thromboembolism and thromboprophylaxis following total knee/hip replacement surgery. In addition, rivaroxaban (in combination with aspirin alone or aspirin and clopidogrel) is used in the prevention of atherothrombotic events following acute coronary syndrome with elevated cardiac biomarkers. In case of severe bleeding complications under DOACs treatment, antidotes are available; idarucizumab for dabigatran reversal and andexanet alfa for rivaroxaban and apixaban.

The preoperative management of dabigatran and its specific antidote idarucizumab in patients with nonvalvular atrial fibrillation: Case reports

Dabigatran is a novel oral anticoagulant preferred due to its ease of use, favorable pharmacokinetics, decreased potential for drug-drug interactions, and the lack of monitoring requirements. With the growing use of dabigatran, it is important to highlight that dabigatran increases the risk of hemorrhage after some procedures. Therefore, when dabigatran is used before the elective or urgent procedures, it is necessary to compare the thromboembolic event risk with the relative risk of bleeding. Before the approval of a reversal agent, the lack of specific antidotes had been the major limitation against the widespread utilization of dabigatran. In October 2015, idarucizumab, a humanized monoclonal antigen-binding antibody fragment capable of reversing the anticoagulant activity of dabigatran, has been introduced into the market to be used in lifethreatening bleeding or urgent surgery. In this manuscript, the preoperative management of dabigatran and the initial experience of using idarucizumab in a patient with nonvalvular atrial fibrillation were described. We propose that the option of dabigatran reversal needs to be considered in patients with nonvalvular atrial fibrillation. However, additional research is needed to define optimal perioperative management of dabigatran and other novel oral anticoagulants, especially in high bleeding risk patients, and to determine whether pre-procedure coagulation testing should be performed.

Role of direct oral anticoagulants in patients with kidney disease

The anticoagulation field is experiencing a renaissance that began with regulatory approval of the direct thrombin inhibitor dabigatran, a direct oral anticoagulant (DOAC), in 2010. The DOAC medication class has rapidly evolved to include the additional approval of 4 direct factor Xa inhibitors. Commensurately, DOAC use has increased and collectively account for the majority of new anticoagulant prescriptions. Despite exclusion of patients with moderate-to-severe kidney disease from most pivotal DOAC trials, DOACs are increasingly used in this setting. An advantage of DOACs is similar or improved antithrombotic efficacy with less bleeding risk when compared with traditional agents. Several post hoc analyses, retrospective studies, claims data studies, and meta-analyses suggest that these benefits extend to patients with kidney disease. However, the lack of randomized controlled trial data in specific kidney disease settings, with their unique pathophysiology, should be a call to action for the kidney community to systematically study these agents, especially because early data suggest that DOACs may pose less risk of anticoagulant-related nephropathy than do vitamin K antagonists. Most DOACs are renally cleared and are significantly protein bound in circulation; thus, the pharmacokinetics of these drugs are influenced by reduced renal function and proteinuria. DOACs are susceptible to altered metabolism by P-glycoprotein inhibitors and inducers, including drugs commonly used for the management of kidney disease comorbidities. We summarize the currently available literature on DOAC use in kidney disease and illustrate knowledge gaps that represent important opportunities for prospective investigation.

Periprocedural Anticoagulation Management For Nonoperating Room Anesthesia Procedures: A Clinical Guide

Non-operating room anesthesia presents unique challenges for anesthesiologists. Limited preprocedural optimization and unfamiliarity with the location and procedure itself add to the difficulties in delivering safe care for these patients. Management of chronic oral anticoagulation can prove especially problematic since risks of bleeding for non-operating room procedures vary widely and differ from traditional surgeries. In addition, many physicians may not be familiar with the growing number of newly approved oral anticoagulants and their periprocedural management. This review will examine common non-operating procedures, their risks of bleeding, as well as pharmacokinetics of oral anticoagulants available on the market and periprocedural management options.

The efficacy and safety of direct oral anticoagulants in patients with chronic renal insufficiency: A review of the literature

Direct oral anticoagulants (DOACs) have been shown to be superior to vitamin K antagonists (VKAs) in regards to safety and efficacy in numerous clinical trials and are now the preferred oral anticoagulant by multiple professional societies. However, patients with significant levels of organ dysfunction were excluded from all major clinical trials, leaving the clinical benefit in these subsets uncertain. Patients with chronic kidney disease (CKD) specifically often require anticoagulation for acute or long-term indications such as venous thromboembolism, atrial fibrillation, or mechanical heart valves. The efficacy and safety of anticoagulation in patients with renal failure is less certain, however, particularly with DOACs which have altered pharmacokinetics in patients with renal failure and limited observational data on their use in this population. In this review, we compile the most up to date data on the DOAC use in patients with CKD. DOAC use in patients with ESRD and advanced CKD is increasing despite the presence of a clear benefit, and with the potential for increased risk of bleeding compared to warfarin. Apixaban has the greatest amount of outcomes research supporting its use over warfarin in this patient population; however, further research on DOAC safety and efficacy in those with advanced CKD is still needed.