scholarly journals Laboratory Monitoring of Direct Oral Anticoagulants (DOACs)

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 445
Author(s):  
Claire Dunois
Keyword(s):  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Oral Intake ◽  
Time Profile ◽  
Fixed Dose ◽  
Thrombin Time ◽  
Laboratory Methods ◽  
Gold Standard Method ◽  
Daily Oral Intake ◽  
Specific Standard

The introduction of direct oral anticoagulants (DOACs), such as dabigatran, rivaroxaban, apixaban, edoxaban, and betrixaban, provides safe and effective alternative to previous anticoagulant therapies. DOACs directly, selectively, and reversibly inhibit factors IIa or Xa. The coagulation effect follows the plasma concentration–time profile of the respective anticoagulant. The short half-life of a DOAC constrains the daily oral intake. Because DOACs have predictable pharmacokinetic and pharmacodynamic responses at a fixed dose, they do not require monitoring. However in specific clinical situations and for particular patient populations, testing may be helpful for patient management. The effect of DOACs on the screening coagulation assays such as prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT) is directly linked to reagent composition, and clotting time can be different from reagent to reagent, depending on the DOAC’s reagent sensitivity. Liquid chromatography–mass spectrometry (LC-MS/MS) is considered the gold standard method for DOAC measurement, but it is time consuming and requires expensive equipment. The general consensus for the assessment of a DOAC is clotting or chromogenic assays using specific standard calibrators and controls. This review provides a short summary of DOAC properties and an update on laboratory methods for measuring DOACs.

scholarly journals Azolo[1,5-a]pyrimidines and Their Condensed Analogs with Anticoagulant Activity

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 274
Author(s):  
Konstantin V. Savateev ◽  
Victor V. Fedotov ◽  
Vladimir L. Rusinov ◽  
Svetlana K. Kotovskaya ◽  
Alexandr A. Spasov ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Anticoagulant Activity ◽  
Dabigatran Etexilate ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Antiviral Agents ◽  
Multiple Organ ◽  
Thrombin Time ◽  
Cytokine Storm ◽  
Reference Drug

Hypercytokinemia, or cytokine storm, is one of the severe complications of viral and bacterial infections, involving the release of abnormal amounts of cytokines, resulting in a massive inflammatory response. Cytokine storm is associated with COVID-19 and sepsis high mortality rate by developing epithelial dysfunction and coagulopathy, leading to thromboembolism and multiple organ dysfunction syndrome. Anticoagulant therapy is an important tactic to prevent thrombosis in sepsis and COVID-19, but recent data show the incompatibility of modern direct oral anticoagulants and antiviral agents. It seems relevant to develop dual-action drugs with antiviral and anticoagulant properties. At the same time, it was shown that azolo[1,5-a]pyrimidines are heterocycles with a broad spectrum of antiviral activity. We have synthesized a new family of azolo[1,5-a]pyrimidines and their condensed polycyclic analogs by cyclocondensation reactions and direct CH-functionalization and studied their anticoagulant properties. Five compounds among 1,2,4-triazolo[1,5-a]pyrimidin-7-ones and 5-alkyl-1,3,4-thiadiazolo[3,2-a]purin-8-ones demonstrated higher anticoagulant activity than the reference drug, dabigatran etexilate. Antithrombin activity of most active compounds was confirmed using lipopolysaccharide (LPS)-treated blood to mimic the conditions of cytokine release syndrome. The studied compounds affected only the thrombin time value, reliably increasing it 6.5–15.2 times as compared to LPS-treated blood.

scholarly journals ORAL ANTICOAGULANTS IN THE TREATMENT OF VENOUS THROMBOEMBOLIC COMPLICATIONS: FOCUS ON APIXABAN

2017 ◽  
pp. 56-62 ◽  
Author(s):  
M. Yu. Gilyarov ◽  
E. V. Konstantinova
Keyword(s):  
Vitamin K ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Factor Xa ◽  
Vitamin K Antagonist ◽  
Fixed Dose ◽  
Vein Thrombosis ◽  
Venous Thromboembolic ◽  
Deep Vein

Venous thromboembolism (VTE), comprising deep vein thrombosis and pulmonary embolism, is a common condition associated with a significant clinical and economic burden. Anticoagulant therapy is the mainstay of treatment for VTE. Current guidelines recommend the use of either low molecular weight heparins or fondaparinux overlapping with and followed by a vitamin K antagonist for the initial treatment of VTE, with the vitamin K antagonist continued when long-term anticoagulation is required. These traditional anticoagulants have practical limitations that have led to the development of direct oral anticoagulants that directly target either Factor Xa or thrombin and are administered at a fixed dose without the need for routine coagulation monitoring. The paper reviews results of the trials of apixaban application for treatment and/or long-term secondary prevention of VTE. The paper analyses effectiveness and safety of apixaban in different groups of patients, as well as features of apixaban application in every day practice.

scholarly journals Direct oral anticoagulant monitoring: what laboratory tests are available to guide us?

Hematology ◽  
2019 ◽  
Vol 2019 (1) ◽  
pp. 194-197 ◽  
Author(s):  
Ravi Sarode
Keyword(s):  
Clinical Decision Making ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Rapid Assessment ◽  
Clinical Decision ◽  
The United States ◽  
Thrombin Inhibitor ◽  
Thrombin Time ◽  
Clinical Scenarios

Abstract Direct oral anticoagulants (DOACs) are increasingly used in the treatment and prophylaxis of thromboembolism because of several advantages over vitamin K antagonists, including no need for laboratory monitoring. However, it has become increasingly important in certain clinical scenarios to know either actual DOAC concentration (quantitative) or presence of DOAC (qualitative). These clinical conditions include patients presenting with major bleeding or requiring urgent surgery who may need a reversal or hemostatic agent, extremes of body weight, failed therapy, etc. Prothrombin time and activated partial thromboplastin time are variably affected by factor Xa inhibitors (FXaIs) and direct thrombin inhibitor (DTI), respectively, depending on reagents’ sensitivity, and hence, they cannot be relied on confidently. Thrombin time is highly sensitive to very low amounts of DTI; thus, normal value rules out a clinically significant amount. Liquid chromatography mass spectrometry accurately measures DOAC levels but is clinically impractical. Dilute thrombin time and ecarin-based assays using appropriate calibrators/controls provide an accurate DTI level. Anti-Xa assay using corresponding FXaI calibrators/controls provides accurate drug levels. However, these assays are not readily available in the United States compared with some other parts of the world. Heparin assays using anti-Xa activity often have a linear relationship with calibrated FXaI assays, especially at the lower end of on-therapy levels, and they may provide rapid assessment of drug activity for clinical decision making. Currently, there is very limited knowledge of DOAC effect on viscoelastic measurements. Although there is uniformity in expression of DOAC concentrations in nanograms per milliliter, a universal FXaI DOAC assay is urgently needed.

Safety and Feasibility of Treatment with Rivaroxaban in Children for Non-Routine Indications: A Case Series Analysis

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5014-5014 ◽  
Author(s):  
Kathryn E. Dickerson ◽  
Ravi Sarode ◽  
Ayesha Zia
Keyword(s):  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Anticoagulation Therapy ◽  
Case Series ◽  
Bleeding Complications ◽  
Fixed Dose ◽  
The Mean ◽  
Recurrent Vte

Background. Anticoagulation therapy is the cornerstone of acute treatment of venous thromboembolism (VTE) and for prevention of recurrent VTE. The need for anticoagulation is increasing in children, largely in part due to increasing VTE rates. Conventional anticoagulants, including heparin, low-molecular weight heparins (LMWH), Fondaparinux, and vitamin K antagonists (VKA) are widely used in children but have limitations. Standard of care management with these agents is plagued with the trade-off between daily or twice daily injections or frequent monitoring of therapeutic effect. The advent of direct oral anticoagulants (DOACs) have catalyzed significant changes in the therapeutic landscape of VTE management. DOACs have been evaluated for safety and efficacy in large, randomized controlled trials in the treatment and prevention of VTE in adults, with results that are comparable to conventional therapy. None of the current DOACs have FDA-approved indications and dosing in children yet. Off-label use of these agents is largely based on adult data and doses, and is increasing at many Children's Hospitals across US. Rivaroxaban, a DOAC, is a factor Xa inhibitor with predictable pharmacokinetic and pharmacodynamics properties. Methods. We describe a case series of 8 unique pediatric cases, treated with Rivaroxaban, for a variety of non-routine indications, due either to adverse effects, intolerability of LMWH or VKA or the need for ongoing, long term anticoagulation. Rivaroxaban was started after informed consent and assent from parents or patients respectively, and was initiated at a fixed dose but titrated to a final dose after monitoring of trough and peak Rivaroxaban levels (Aniara, West Chester,OH, USA). Results. The mean age of patients in this case series is 14 years (median: 16, range 3-17) (see Table). The most common indication to use Rivaroxaban was the need for long term anticoagulation after having completed therapeutic anticoagulation, except in two patients, one of whom developed warfarin skin necrosis due to protein C deficiency and another with heparin induced thrombocytopenia. Only two patients needed dose adjustments to achieve target trough and peak drug levels. The mean duration of follow-up is 9 months (median= 5.5; range 3-24) (see Table) at this time. None of the patients developed recurrent VTE while on Rivaroxaban. A soft tissue traumatic bleed occurred in one patient which was treated with holding off the drug for 48 hours. No other bleeding complications were observed. Conclusions. Clinical application of DOACs in a real world clinical setting, including strong thrombophilia and malignancy, results in treatment profile of high efficacy and safety in children; however, larger studies are needed to validate these findings. Disclosures Sarode: CSL Behring: Consultancy, Honoraria.

scholarly journals Reversal of direct oral anticoagulants: a practical approach

Hematology ◽  
2016 ◽  
Vol 2016 (1) ◽  
pp. 612-619 ◽  
Author(s):  
Andrew W. Shih ◽  
Mark A. Crowther
Keyword(s):  
Phase 1 ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Antibody Fragment ◽  
Factor Xa ◽  
Factor Xa Inhibitors ◽  
Severe Bleeding ◽  
Thrombin Time ◽  
Ancillary Benefits ◽  
Reversal Agents

Abstract Direct oral anticoagulants (DOACs) have at least noninferior efficacy compared with other oral anticoagulants and have ancillary benefits, including overall better safety profiles, lack of the need for routine monitoring, rapid onset of action, and ease of administration. Reversal of these agents may be indicated in certain situations such as severe bleeding and for perioperative management. DOAC-associated bleeding should be risk stratified: patients with moderate or severe bleeding should have the DOAC discontinued and reversal strategies should be considered. Laboratory testing has limited utility in the acute management of bleeding; thrombin time and activated partial thromboplastin time may be useful for excluding clinically relevant levels of dabigatran. Prothrombin time is potentially useful for rivaroxaban and edoxaban, but calibrated anti-Xa assays are optimal for determining clinically relevant levels of factor Xa inhibitors. Because specific reversal agents are not widely available, supportive care and interventions for local hemostasis remain the cornerstones of therapy in the patient with DOAC-associated bleeding. Nonspecific reversal agents should be considered only in the event of severe bleeding because their efficacy is unknown, and they are associated with risk of thrombosis. Recent results from phase 3/4 studies demonstrate efficacy for an antidote to dabigatran (idarucizumab, a monoclonal antibody fragment with specificity for dabigatran) and an antidote to factor Xa inhibitors (andexanet alfa, a recombinant and inactive form of factor Xa that binds inhibitors). A universal reversal agent (ciraparantag) for many anticoagulants, including the DOACs, shows promise in results from phase 1 and 2 studies.

scholarly journals Direct Oral Anticoagulants in Patients with Obesity and Atrial Fibrillation: Position Paper of Italian National Association of Hospital Cardiologists (ANMCO)

2021 ◽  
Vol 10 (18) ◽  
pp. 4185
Author(s):  
David Mocini ◽  
Stefania Angela Di Fusco ◽  
Edoardo Mocini ◽  
Lorenzo Maria Donini ◽  
Carlo Lavalle ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
High Body Mass Index ◽  
Normal Weight ◽  
Phase Iii ◽  
Fixed Dose ◽  
Pivotal Phase ◽  
Phase Iii Trials

The use of the direct oral anticoagulants dabigatran, rivaroxaban, apixaban and edoxaban (DOACs) offers some major advantages over warfarin and other vitamin K antagonists (VKAs). One advantage is the possibility to use a fixed dose in normal-weight patients, overweight patients and patients with obesity. However, the “one size fits all” strategy raised a concern regarding the possibility to undertreat patients with a high body mass index. No randomized controlled trials (RCTs) have ever compared VKAs and DOACs in this population. We analyzed data from the literature on DOAC pharmacokinetics and pharmacodynamics, results from the four pivotal phase III trials on non-valvular atrial fibrillation, retrospective observational studies and metanalyses. While we are aware of the limitation imposed by the absence of specific RCTs, we propose the position of the Italian Association of Hospital Cardiologists (ANMCO) on the use of DOACs in patients with obesity based on the existing evidence.

scholarly journals Monitoring and reversal of direct oral anticoagulants

Hematology ◽  
2015 ◽  
Vol 2015 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Adam Cuker ◽  
Deborah Siegal
Keyword(s):  
Prothrombin Complex Concentrate ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Antibody Fragment ◽  
Factor Xa ◽  
Factor Xa Inhibitors ◽  
Severe Bleeding ◽  
Thrombin Time ◽  
Reversal Agents ◽  
Routine Monitoring

Abstract Although the direct oral anticoagulants (DOACs) do not require routine monitoring and reduce bleeding compared with warfarin, there are special circumstances in which laboratory measurement or reversal of their anticoagulant effect may be indicated. The dilute thrombin time and ecarin-based assays are able to quantify dabigatran across a broad range of concentrations, but are not widely available. A normal thrombin time excludes clinically relevant levels and a normal activated partial thromboplastin time probably excludes excess levels of dabigatran. Factor Xa inhibitors may be quantified with an anti-Xa assay calibrated with drug-specific standards. A normal prothrombin time probably excludes excess levels of rivaroxaban and edoxaban, but not apixaban. Patients with minor and moderate DOAC-associated bleeding can be treated with supportive care and general hemostatic measures. Nonspecific reversal agents (eg, prothrombin complex concentrate, activated prothrombin complex concentrate) are of unproven benefit, carry a risk of thrombosis, and should be reserved for severe bleeding. Specific reversal agents, such as idarucizumab (a monoclonal antibody fragment that binds dabigatran) and andexanet alfa (a recombinant factor Xa variant that binds factor Xa inhibitors but lacks coagulant activity), are in clinical development.

Determination of anticoagulant activity of direct oral anticoagulants: the current state of knowledge and a single center experience

2017 ◽  
Vol 53 (3) ◽  
pp. 161-168
Author(s):  
Tadeusz Góralczyk ◽  
Anetta Undas
Keyword(s):  
Anticoagulant Activity ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Thrombin Time ◽  
Routine Laboratory ◽  
Pharmacological Mechanism ◽  
Emergency Procedures ◽  
Single Center Experience

Direct oral anticoagulants (DOACs) increasingly replace vitamin K antagonists in the treatment and prevention of venous thromboembolism, and stroke prevention in non-valvular atrial fibrillation. Due to their predictable pharmacological mechanism, no diet restrictions and lack of interaction with most drugs, DOACs do not require routine laboratory monitoring. However, in cases of suspected concentrations beyond the expected range or a need for an emergent surgical procedure, access to laboratory methods for reliable DOACs determination is necessary. In a routine laboratory, the anticoagulant effect of dabigatran can be determined using methods based on ecarin or the modified dilute thrombin time. Rivaroxaban, apixaban and edoxaban may be measured using the chromogenic anti-FXa assays. Our own experience (the longest in Poland) from the John Paul II Hospital laboratory with the 24-hour availability of DOACs measurement involves determinations of dabigatran (n = 136), rivaroxaban (n = 374) and apixaban (n = 22) in outpatients and hospitalized patients between May 2013 and April 2017. Determination of the level of DOACs should be available 24/7 in highly specialized medical centers, especially in those which perform emergency procedures for treating patients with acute stroke and hemorrhages.

Monitoring and reversal of direct oral anticoagulants

Hematology ◽  
2015 ◽  
Vol 2015 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Adam Cuker ◽  
Deborah Siegal
Keyword(s):  
Prothrombin Complex Concentrate ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Antibody Fragment ◽  
Factor Xa ◽  
Factor Xa Inhibitors ◽  
Severe Bleeding ◽  
Thrombin Time ◽  
Reversal Agents ◽  
Routine Monitoring

Although the direct oral anticoagulants (DOACs) do not require routine monitoring and reduce bleeding compared with warfarin, there are special circumstances in which laboratory measurement or reversal of their anticoagulant effect may be indicated. The dilute thrombin time and ecarin-based assays are able to quantify dabigatran across a broad range of concentrations, but are not widely available. A normal thrombin time excludes clinically relevant levels and a normal activated partial thromboplastin time probably excludes excess levels of dabigatran. Factor Xa inhibitors may be quantified with an anti-Xa assay calibrated with drug-specific standards. A normal prothrombin time probably excludes excess levels of rivaroxaban and edoxaban, but not apixaban. Patients with minor and moderate DOAC-associated bleeding can be treated with supportive care and general hemostatic measures. Nonspecific reversal agents (eg, prothrombin complex concentrate, activated prothrombin complex concentrate) are of unproven benefit, carry a risk of thrombosis, and should be reserved for severe bleeding. Specific reversal agents, such as idarucizumab (a monoclonal antibody fragment that binds dabigatran) and andexanet alfa (a recombinant factor Xa variant that binds factor Xa inhibitors but lacks coagulant activity), are in clinical development.

scholarly journals Idarucizumab, a Specific Antidote for Dabigatran: Immediate, Complete and Sustained Reversal of Dabigatran Induced Anticoagulation in Elderly and Renally Impaired Subjects

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 344-344 ◽  
Author(s):  
Stephan Glund ◽  
Joachim Stangier ◽  
Michael Schmohl ◽  
Viktoria Moschetti ◽  
Wouter Haazen ◽  
...  
Keyword(s):  
Vitamin K Antagonists ◽  
Dabigatran Etexilate ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Anticoagulant Effect ◽  
Thrombin Time ◽  
Double Blind ◽  
Male And Female ◽  
Increased Risk ◽  
Pharmacologically Active

Abstract Introduction Oral anticoagulation is an effective therapy to prevent and treat thromboembolic events. So far, Vitamin K antagonists have been the main drug of choice. Recently, the advent of the direct oral anticoagulants (DOAC) has changed medical practice significantly; nevertheless all anticoagulants are associated with an increased risk of bleeding. Bleeding management can be achieved through established therapies; however specific antidotes are not yet available for these agents to further facilitate patient management in cases needed. Previously the dabigatran antidote (idarucizumab) has demonstrated immediate, complete and sustained reversal of dabigatran induced anti-coagulation in healthy male volunteers. In the present study it was determined whether and to what extent doses of up to 5 g idarucizumab would reverse the anticoagulant effects of dabigatran in male and female healthy mid-aged, elderly and renally impaired volunteers. In addition, it was tested whether oral intake of dabigatran etexilate 24 hrs after idarucizumab treatment could restore dabigatran related anticoagulation. It was further tested if a second administration of idarucizumab 2 months later was safe and well tolerated. Methods Safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of idarucizumab were investigated in a randomized, double-blind, placebo controlled two-way cross-over study in 46 male and female volunteers. Dabigatran etexilate (DE), 220 mg bid in healthy subjects and 150 mg bid in subjects with mild or moderate renal impairment (CLCR60 to <90 or 30 to <60 [mL/min], respectively) was given over 4 days to achieve the steady state conditions. Idarucizumab doses of 1 g, 2.5 g, 5 g or 5 g given as 2x2.5 g one hour apart were administered as 5 min i.v. infusion 2 hrs after the last dose of DE. Concentrations of unbound dabigatran were determined as a measure of pharmacologically active dabigatran. The anticoagulant effect of dabigatran and its reversal were assessed by coagulation time measurements, including diluted Thrombin Time (dTT, Hemoclot® DTI assay), Ecarin Clotting Time (ECT) and activated Partial Thromboplastin Time (aPTT). Results All administered doses of idarucizumab were safe and well tolerated. PK measurements of unbound dabigatran indicated that idarucizumab binding and thus reversal of the anticoagulant effect of dabigatran occurred immediately after end of infusion. Prolongation of clotting times induced by dabigatran was reversed to baseline at the end of the 5 minute infusion of the antidote. This was consistently demonstrated by all clotting assays. Sustained reversal over the entire observation period was observed for idarucizumab doses of 2.5 g, 5 g and 2x2.5 g. For the 1g dose, there was partial return of dabigatran induced anticoagulation around 2-4 hours after i.v. infusion. Also a second administration of idarucizumab (two months after the first) was safe and resulted in complete reversal. In addition, PD and PK measurements at selected time points and in comparison to placebo treatment confirmed that effective dabigatran anticoagulation could be re-established 24 hours after administration of idarucizumab. Conclusions The dabigatran antidote, idarucizumab, was well tolerated under all conditions tested. The administration of 5 g or 2x2.5 g led to sustained reversal of dabigatran induced anticoagulation in male and female subjects of different age and renal function. In addition, idarucizumab administered 2 months apart achieved the same degree of reversal. Dabigatran anticoagulation could be re-established 24 hrs after idarucizumab dosing. These results support the use of a total dose of 5 g idarucizumab as an effective dose in further clinical testing. Disclosures Glund: Boehringer Ingelheim: Employment. Off Label Use: Idarucizumab, a specific antidote for dabigatran, is in clinical development.. Stangier:Boehringer Ingelheim: Employment. Schmohl:Boehringer Ingelheim: Employment. Moschetti:Boehringer Ingelheim: Employment. Haazen:SGS Life Science Services (contracted by Boehringer Ingelheim to conduct the study): Employment. De Smet:SCS Boehringer Ingelheim Comm. V.: Employment. Gansser:Boehringer Ingelheim: Employment. Norris:Boehringer Ingelheim: Employment. Lang:Boehringer Ingelheim: Employment. Reilly:Boehringer Ingelheim: Employment.

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