Antidotes for the direct oral anticoagulants: What news?

Perioperative Management of Oral Anticoagulants and Antiplatelet Therapy in Hand and Wrist Surgery

There is wide variability in the management of patients on antithrombotic therapy requiring surgery of the hand and wrist. There are no specific guidelines regarding whether to temporarily cease or continue oral anticoagulants and antiplatelet agents. Discontinuation of these medications before surgery can lead to perioperative thromboembolic or ischemic events. On the other hand, continuation can lead to intraoperative or postoperative bleeding complications. This review discusses various anticoagulants and antiplatelet agents with special considerations for their management, analyzes the current literature, summarizes current recommendations, and provides direction for additional research.

Evaluation of the Hemostatic Effect of an Innovative Tissue Adhesive during Extraction Therapy under Rivaroxaban in a Rodent Model

An increase in rivaroxaban therapies is associated with increased numbers of postoperative bleeding despite the use of hemostatic sponges, which are currently the gold standard treatment. VIVO has shown promising hemostatic results, favorable tissue properties, and ease of application, although it has not yet been used in the oral cavity. The aim of this study was to evaluate the hemostatic properties of VIVO in the extraction sockets of 31 rodents and compare this to gelatin sponge (GSP) therapy. At rivaroxaban concentrations of 264.10 ± 250.10 ng/mL, 62 extraction sockets were generated, of which 31 were treated with VIVO and 31 with GSP. The duration time, early and late bleeding events, and wound healing score were determined. Histologic examinations of the tissues were performed after 5 days. VIVO presented a longer procedure, 1.26 ± 0.06 min, but a significantly shorter bleeding time, 0.14 ± 0.03 min. There was no difference between the two groups in terms of the severity and timing of bleeding. More minor early bleeding events were observed for GSP. VIVO showed a significantly better healing score, with favorable histological results. In an animal study, VIVO showed promising hemostatic properties after tooth extraction under ongoing anticoagulative therapy.

Present Knowledge on Direct Oral Anticoagulant and Novel Oral Anti Coagulants and Their Specific Antidotes: A Comprehensive Review Article

Thromboembolic diseases are one of the leading causes of morbidity and mortality worldwide. For a long time, heparin and Vitamin K antagonist (VKA) drugs were used for treatment and prophylaxis of the thromboembolic diseases. The development of newer direct and novel oral anticoagulant medications (DOACs/NOACs) has changed clinical practice significantly. Lesser monitoring, ease with dosing, less drug interactions have made these drugs useful to the providers and the patients. But these drugs have bleeding as a side effect. There is ongoing research on the specific antidotes of these anticoagulants in case of life-threatening bleeding. Though the use of the DOACs and NOACs have increased, there is still not enough clinical evidence about the specific antidotes of these medications. Unlike heparin or VKA, reversal of life-threatening bleeding in the setting of DOAC use is still a clinical challenge. We need more data on the dose, pharmacokinetics, and clinical efficacy of those antidotes. Authors have reviewed articles on DOACs and their antidotes in Pubmed and also in the clinical trial website. Specific antidotes including Idarucizumab for Dabigatran, Andexanet alfa for factor Xa inhibitors are being used to reverse the actions of the anticoagulants. Ciraparantag is a universal antidote for the DOACs, which is still under investigation. FXaI16L is currently being investigated as a potential universal antidote for multiple anticoagulants, including dabigatran and rivaroxaban. Though mostly safe, the use of DOACs can still carry a risk of severe bleeding in patients. More data on the use of the antidotes is required to reverse the side effect of DOACs if clinically indicated.

Knowledge and medication adherence of oral anticoagulant-taking patients in Vietnam

Background

Oral anticoagulants for venous thromboembolism are not thoroughly managed in ambulatory settings in low-/middle-income countries, primarily because of patients' neglect of medication knowledge and adherence.

Objectives

This study was conducted to investigate patient knowledge, adherence, and the associated factors at a Vietnamese tertiary hospital, serving as a reference for educational programs in other local and regional health care facilities.

Methods

A randomly recruited cross-sectional study was conducted on patients using vitamin K antagonists (VKA) or direct oral anticoagulants (DOAC). The primary and secondary outcomes were the knowledge score (in percent) and adherence to oral anticoagulants. Student's t-tests or chi-squared tests were used to compare the crude differences in mean or proportion between patients taking VKA and DOAC. Regression models were conducted to adjust the potential confounders and determine factors associated with patient knowledge and adherence.

Results

A total of 199 patients were included. After adjusting for potential confounders, patients receiving a DOAC had similar knowledge scores and levels of adherence compared with those taking VKA, with both groups being suboptimal. Previous counseling was associated with higher knowledge. Better medication knowledge, female sex, and no history of venous thromboembolism were associated with better adherence.

Conclusion

Good knowledge and adherence of oral anticoagulant-taking patients remain limited in Southeast Asian clinical practice. Further studies in similar settings should examine the associations between these factors and the effectiveness of the regimens. More effective measures targeting patient knowledge and adherence should be implemented to optimize anticoagulation therapy, improve the patients' outcomes, and mitigate the associated adverse effects.

Advanced delivery strategies facilitating oral absorption of heparins

Heparins show great anticoagulant effect with few side effects, and are administered by subcutaneous or intravenous route in clinics. To improve patient compliance, oral administration is an alternative route. Nonetheless, oral administration of heparins still faces enormous challenges due to the multiple obstacles. This review briefly analyzes a series of barriers ranging from poorly physicochemical properties of heparins, to harsh biological barriers including gastrointestinal degradation and pre-systemic metabolism. Moreover, several approaches have been developed to overcome these obstacles, such as improving stability of heparins in the gastrointestinal tract, enhancing the intestinal epithelia permeability and facilitating lymphatic delivery of heparins. Overall, this review aims to provide insights concerning advanced delivery strategies facilitating oral absorption of heparins.

Patients Taking Direct Oral Anticoagulants (DOAC) Undergoing Oral Surgery: A Review of the Literature and a Proposal of a Peri-Operative Management Protocol

Patients on anticoagulant therapy for the prevention of cardiovascular accidents present an increased risk of bleeding following dental and oral surgery. Four recently introduced non-vitamin K antagonist oral anticoagulants, namely dabigatran etexilate (direct thrombin inhibitor), rivaroxaban, apixaban, and edoxaban (Xa factor direct inhibitor), are widely spreading for convenience of use compared to the older drug class. Dental management of patients taking these drugs has substantial differences compared to patients on vitamin K antagonist therapy. Anticoagulation is not assessed directly through a hematological test, but indirectly by renal function. The interventions must be scheduled at the time of minimum blood concentration of the drug. Bleeding can occur even after several days following the surgery. The interaction with drugs administered for dental care must be carefully evaluated. The peri-operative diet can influence the risk of bleeding. Local measures favoring coagulation must be adopted. The interventions with higher risk must be divided into multiple less invasive interventions. Although antidotes exist for these drugs, their use does not seem necessary for dental interventions that have been planned optimally. Furthermore, in this review of the literature a decision protocol is proposed for the evaluation of the suspension of the anticoagulant drug before oral surgery. Cessation of any anticoagulant should only be made in consultation with the patient’s general practitioner/cardiologist, who will weigh up the risk of bleeding from the proposed procedure with the risk of thrombosis/stroke in each individual patient.

Implementation of a standardised annual anticoagulation specialist review in primary care

An increasing number of patients are being prescribed direct oral anticoagulants (DOACs), while the patients who remain on warfarin are becoming more complex. There is currently a lack of a standardised anticoagulation review for patients in primary care, resulting in potentially preventable harm events. Our aim was to implement a new service, where a standardised review is carried out by a specialist multidisciplinary secondary care anticoagulation team. Overall, the implementation of a standardised review resulted in better optimisation of anticoagulation management for patients taking either a DOAC or a warfarin. Of the 172 eligible patients prescribed warfarin, 47 (27%) chose to switch a DOAC. The average time in therapeutic range for patients on warfarin before and after the pilot increased from 73.5% to 75%. Of 482 patients taking a DOAC, 35 (7%) were found to be on incorrect dose. In 32 (91%) of 35 patients, the dose was amended after notifying the patient's general practitioner. We also found a significant number of patients inappropriately prescribed concomitant medication such as antiplatelet or non-steroidal anti-inflammatory drugs, potentially putting the patients at an elevated risk of bleeding. While further research is needed; we believe the results of this pilot can be used to help build a case to influence the commissioning of anticoagulation services. Secondary care anticoagulation teams, like our own, may be well-placed to provide or support such services, by working across the primary care and secondary care interface to support our primary care colleagues.

An Update on the Reversal of Non-Vitamin K Antagonist Oral Anticoagulants

Non-vitamin K antagonist oral anticoagulants (NOACs) include thrombin inhibitor dabigatran and coagulation factor Xa inhibitors rivaroxaban, apixaban, edoxaban, and betrixaban. NOACs have several benefits over warfarin, including faster time to the achieve effect, rapid onset of action, fewer documented food and drug interactions, lack of need for routine INR monitoring, and improved patient satisfaction. Local hemostatic measures, supportive care, and withholding the next NOAC dose are usually sufficient to achieve hemostasis among patients presenting with minor bleeding. The administration of reversal agents should be considered in patients on NOAC's with major bleeding manifestations (life-threatening bleeding, or major uncontrolled bleeding), or those who require rapid anticoagulant reversal for an emergent surgical procedure. The Food and Drug Administration (FDA) has approved two reversal agents for NOACs: idarucizumab for dabigatran and andexanet alfa for apixaban and rivaroxaban. The American College of Cardiology (ACC), American Heart Association (AHA), and Heart Rhythm Society (HRS) have released an updated guideline for the management of patients with atrial fibrillation that provides indications for the use of these reversal agents. In addition, the final results of the ANNEXA-4 study that evaluated the efficacy and safety of andexanet alfa were recently published. Several agents are in different phases of clinical trials, and among them, ciraparantag has shown promising results. However, their higher cost and limited availability remains a concern. Here, we provide a brief review of the available reversal agents for NOACs (nonspecific and specific), recent updates on reversal strategies, lab parameters (including point-of-care tests), NOAC resumption, and agents in development.

A New Option for Reversing the Anticoagulant Effect of Factor Xa Inhibitors: Andexanet Alfa (ANDEXXA)

The use of direct oral anticoagulants over traditional warfarin has increased in the United States over the past 10 years because of advantages such as ease of use, predictable pharmacokinetic response, and safety. In 2015, the U.S. Food and Drug Administration approved idarucizumab (Praxbind) for the reversal of the direct thrombin inhibitor dabigatran, but no reversal agent has been available for oral factor Xa (FXa) inhibitors until recently. Andexanet alfa was approved in May 2018, under the brand name ANDEXXA, for the reversal of 2 of FXa inhibitors, apixaban and rivaroxaban, when life-threatening or uncontrolled bleeding occurs. This accelerated approval was based on change in anti-FXa activity from baseline that indicated a reversal of the anticoagulant effect. Any expanded Food and Drug Administration indication will be contingent on results demonstrating improved hemostasis and efficacy for reversing other FXa inhibitors.