Anticoagulation antidotes

INTRODUCTION: Andexanet alfa (AA) - zhzo, recombinant coagulation factor Xa, is an approved antidote for oral Xa inhibitors (apixaban and rivaroxaban). Unfractionated heparin (UFH) is commonly used for therapeutic, interventional, and surgical indications. Protamine sulfate (PrSO4 ) is frequently used to neutralize UFH. This study aimed to investigate the comparative neutralization profiles of AA and PrSO4 for heparins of bovine, ovine, and porcine origin. MATERIALS AND METHODS: The neutralization effect of PrSO4 at 25 µg/ml and AA at 100 µg/ml was studied on an approximate surgical/interventional concentration of heparin by supplementing whole blood with each of the heparins at 25 µg/ml...

Given the growing number of patients receiving direct oral anticoagulant (DOAC), patients requiring rapid neutralization is also increasing in case of major bleedings or urgent surgery/procedures. Idarucizumab is commercialized as a specific antidote to dabigatran while andexanet alfa has gained the Food and Drug Administration and the European Medicines Agency approval as an oral anti-factor Xa inhibitors antidote. Other antidotes or hemostatic agents are still under preclinical or clinical development, the most advanced being ciraparantag...

Venous thromboembolism (VTE) and stroke carry significant mortality and morbidity in cancer patients. Direct oral anticoagulants (DOACs) have been demonstrated to be effective for the treatment of VTE and prevention of stroke in atrial fibrillation (AF). Bleeding rates are variable and are based on the cancer type and the patient's specific risk factors. There are approved specific antidotes for DOAC-associated bleeding. Other strategies are available for bleeding reversal, including the use of prothrombin complex concentrate (PCC)...

Thrombosis, the formation of blood clots within a blood vessel, can lead to severe complications including pulmonary embolism, cardiac arrest, and stroke. The most widely administered class of anticoagulants is heparin-based anticoagulants such as unfractionated heparin (UFH), low-molecular weight heparins (LMWHs), and fondaparinux. Protamine is the only FDA approved heparin antidote. Protamine has limited efficacy neutralizing LMWHs and no reversal activity against fondaparinux. The use of protamine can lead to complications, including excessive bleeding, hypotension and hypersensitivity, and has narrow therapeutic window...

Background: Thromboembolic disease is associated with a high rate of disability or death and gravely jeopardizes people's health and places considerable financial pressure on society. The primary treatment for thromboembolic illness is anticoagulant medication. Fondaparinux, a parenteral anticoagulant medicine, is still used but is confusing due to its disparate domestic and international indications and lack of knowledge about its usage. Its off-label drug usage in therapeutic settings and irrational drug use are also common...

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...

PURPOSE OF REVIEW: The advent of direct oral anticoagulants (DOACs) marks a significant milestone in anticoagulant treatment. However, DOACs can exacerbate bleeding, which is challenging for the treating clinician, especially when combined with traumatic injury. RECENT FINDINGS: In major bleeding associated with DOACs, rapid reversal of the anticoagulant effects is crucial. Recent observational and nonrandomized interventional trials have demonstrated the effectiveness of the specific antidotes andexanet alfa and idarucizumab as well as the unspecific prothrombin complex concentrates (PCCs) to counteract the anticoagulant effects of DOACs...

BACKGROUND: Since the late 2000s, Europe has granted approval for various thrombotic risk-related uses of direct oral anticoagulants (DOACs). Unlike traditional anticoagulants, DOACs do not necessitate routine coagulation monitoring. Nevertheless, clinical practice often encounters bleeding events associated with these medications, making the need for effective reversal strategies evident. OBJECTIVES: The study aims to take stock of current reversal strategies for DOACs, with a particular emphasis on the latest compounds that have been developed or are currently under development...

Andexanet alfa (AA) is a recombinant, inactive analog of human factor Xa (FXa), effectively reversing the effects of its inhibitors - rivaroxaban and apixaban, which are available in Poland. The drug was granted registration after the publication of the ANNEXA-4 trial (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of FXA Inhibitors 4), in which its efficacy in restoring hemostasis in life-threatening hemorrhages in a group of patients using the aforementioned anticoagulants was proven. Hence, AA is now recommended for patients receiving apixaban or rivaroxaban therapy with massive and uncontrollable hemorrhages, including hemorrhagic strokes (HS) and gastrointestinal bleeding...

This study in vitro comprehensively assessed reversal of the anticoagulant effects of rivaroxaban, an oral factor Xa inhibitor, using andexanet alfa and various prothrombin complex concentrate (PCC) products in a battery of tests. In static coagulation assays, andexanet alpha outperformed PCCs except for activated PCC being more effective in standard coagulation times. However, in a flow chamber model mimicking arterial shear, both andexanet alpha and high-concentration PCC restored fibrin formation, but not platelet adhesion...

BACKGROUND: The comparative effectiveness of the specific antidote andexanet alfa vs the nonspecific therapy four-factor prothrombin complex concentrates (4F-PCCs) as reversal agents for direct factor Xa (FXa) inhibitors in severely bleeding patients is unclear. We hypothesised that specific reversal using andexanet alfa would be more effective than a high dose of PCC (50 IU kg-1 ) for reversing the FXa inhibitor rivaroxaban. METHODS: The reversal potential of andexanet alfa, various 4F-PCCs, and activated PCC was investigated ex vivo in human blood anticoagulated with rivaroxaban (37...

In recent times, novel oral anticoagulants (NOACs)/direct oral anticoagulants (DOACs) have emerged as an alternative to the traditionally used Vitamin K oral antagonists (VKA) like warfarin for the treatment of atrial fibrillation (AF). This systematic review and meta-analysis aims to evaluate the efficacy and safety of NOACs in patients with AF and, thus, the related thromboembolic risks and sequelae. Of the 131 published articles we examined, 11 were included in an in-depth systematic review...

BACKGROUND: Both in Germany and internationally there is a vehement controversy about the appropriate time for care of proximal femoral fractures in older patients. The effort to achieve high quality and uniform standards of care culminated in the German healthcare system in the strict requirement of delay-free surgery within 24 h. Until now, in view of their high vulnerability patients who were severely injured were too often operated on late with the reference to a general medical condition that could be improved preoperatively...

BACKGROUND:  For life-threatening or uncontrollable bleeding in association with the thrombin inhibitor dabigatran, the monoclonal antibody fragment idarucizumab is available, and for bleeding in association with the direct factor Xa inhibitors rivaroxaban or apixaban, the modified recombinant FXa protein andexanet is available for reversal. These antidotes represent emergency drugs that are typically used only after performing guideline-compliant multimodal measures. METHODS:  An interdisciplinary group of experienced experts in the fields of angiology, hematology, internal medicine, clinical pharmacology, laboratory medicine, transfusion medicine, anesthesiology, intensive care, and hemostaseology developed recommendations relevant to daily clinical practice based on the current scientific evidence...

OBJECTIVES: Literature is scarce on the management of patients using direct oral anticoagulants (DOACs) undergoing elective, urgent, and emergency surgery. Therefore, we summarize the current evidence and provide literature-based recommendations for the management of patients on DOACs in the peri-operative phase. METHODS: A general literature review was conducted on the pharmacology of DOACs and for recommendations on the management of cardiac surgical patients on DOACs...

Thrombin is a key enzyme involved in blood clotting, and its dysregulation can lead to thrombotic diseases such as stroke, myocardial infarction, and deep vein thrombosis. Thrombin aptamers have the potential to be used as therapeutic agents to prevent or treat thrombotic diseases. Thrombin DNA aptamers developed in our laboratory exhibit high affinity and specificity to thrombin. In vitro assays have demonstrated their efficacy by significantly decreasing Factor II activity and increasing PT and APTT times in both plasma and whole blood...

AIMS: Andexanet alfa, a specific antidote to factor Xa (FXa) inhibitors, has been approved for clinical use in several countries, including Japan, based on the results from the phase 3 trial ANNEXA-4. W e aimed to assess the efficacy and safety of andexanet alfa treatment in FXa inhibitor-related acute major bleeding in patients enrolled for ANNEXA-4 in Japan. METHODS: This prespecified analysis included patients enrolled at Japanese sites in the prospective, open-label, single-arm ANNEXA-4 trial...

Heparin-induced thrombocytopenia (HIT) is a complication caused by administration of the anticoagulant heparin. Although the number of patients with HIT has drastically increased because of coronavirus disease 2019 (COVID-19), the currently used thrombin inhibitors for HIT therapy do not have antidotes to arrest the severe bleeding that occurs as a side effect; therefore, establishment of safer treatments for HIT patients is imperative. Here, we devised a potent thrombin inhibitor based on bivalent aptamers with a higher safety profile via combination with the antidote...

Gastrointestinal (GI) bleeding is one of the most common complications associated with the use of direct oral anticoagulants (DOAC). Clear algorithms exist for the emergency measures in (suspected) GI bleeding, including assessing the medication history regarding anti-platelet drugs and anticoagulants as well as simple coagulation tests during pre-endoscopic management. Platelet transfusions, fresh frozen plasma (FFP), or prothrombin complex concentrate (4F-PCC) are commonly used for optimizing the coagulation status...

Rapidly reversible anticoagulant agents have great clinical potential. Oligonucleotide-based anticoagulant agents are uniquely positioned to fill this clinical niche, as they are able to be deactivated through the introduction of the reverse complement oligo. Once the therapeutic and the antidote oligos meet in solution, they are able to undergo isothermal reassociation to form short, inactive, duplexes that are rapidly secreted via filtration by the kidneys. The formation of the duplexes interrupts the structure of the anticoagulant oligo, allowing normal coagulation to be restored...