Anticoagulation Therapy. Heparins, Factor II and Factor Xa Inhibitors

The association between cancer and venous thromboembolism (VTE) has been well documented in the literature. Prevention and treatment of VTE in cancer patients is imperative. Typically, the mainstay regimen for VTE prevention and treatment has been anticoagulation therapy, unless contraindicated. This therapy consists of unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), factor Xa inhibitor, or vitamin K antagonist (VKA). Current guidelines recommend LMWH over VKA for the treatment of VTE in cancer patients. Factor-specific anticoagulants have been proven safe and effective, and recently factor Xa inhibitors have emerged as a treatment alternative to heparins and VKA. Currently, three factor Xa inhibitors have been identified: fondaparinux (the only one approved so far by the US Food and Drug Administration), idraparinux (in clinical trials), and idrabiotaparinux (in clinical trials). This paper will examine the role of these agents, focusing on fondaparinux, for the prevention and treatment of VTE in cancer patients.

Download Full-text

Utilization of anti–factor Xa levels to guide reversal of oral factor Xa inhibitors in the emergency department

American Journal of Health-System Pharmacy ◽

10.1093/ajhp/zxab326 ◽

2021 ◽

Author(s):

Anne E Zepeski ◽

Brett A Faine ◽

Anna E Merrill ◽

Grerk Sutamtewagul ◽

Sharathkumar Bhagavathi

Keyword(s):

Emergency Department ◽

Anticoagulation Therapy ◽

Factor Xa ◽

Factor Xa Inhibitors ◽

Prothrombin Complex Concentrates ◽

Anticoagulation Reversal ◽

Reversal Agents ◽

Patient Disposition ◽

Rule Out

Abstract Disclaimer In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Purpose Oral factor Xa inhibitors (FXaIs) are increasingly utilized for outpatient anticoagulation therapy; however, laboratory monitoring is not routinely used to assess the safety and efficacy of these agents. We aimed to evaluate the role of chromogenic anti–factor Xa (anti-Xa) assays in the emergency department (ED) in the setting of patients with an acute bleed or requiring emergent procedures. Methods A retrospective review was completed of anti-Xa levels obtained in the ED between June 1, 2019, and April 30, 2020. Data were collected to describe the clinical setting of anti-Xa level collection, oral FXaIs used before admission, administration of reversal agents, and patient disposition to further characterize the role of anti-Xa levels in the management of rivaroxaban and apixaban reversal. Results Thirty anti-Xa levels were included in the final analysis. The median time from sample collection to anti-Xa assay result was 45.9 minutes (interquartile range, 35.3-54.7 minutes). Eleven patients (37%) received anticoagulation reversal after their anti-Xa levels were determined. Anticoagulation reversal agents included either activated prothrombin complex concentrates (aPCCs) or prothrombin complex concentrates (PCCs). Anti-Xa levels were collected in 2 patients who had received PCCs before arrival at our ED. Of the patients with anti-Xa levels below 30 ng/mL, none received aPCCs or PCCs after their anti-Xa levels were determined. Anti-Xa assays were used to rule out the presence of FXaIs in 3 patients. Conclusion This study illustrates the novel role of anti-Xa levels in managing patients with an emergent need for reversal in the ED. The assay may be used to rule out the presence of oral FXaIs and avoid unnecessary administrations of anticoagulation reversal agents.

Download Full-text

Factor II- and factor Xa-inhibitors for prevention and treatment of thromboses / Faktor II- und Faktor Xa-Inhibitoren in der Prävention und Therapie von Thrombosen

LaboratoriumsMedizin ◽

10.1515/jlm.2009.023 ◽

2009 ◽

Vol 33 (2) ◽

pp. 121-127

Author(s):

Matthias Orth

Keyword(s):

Factor Xa ◽

Factor Xa Inhibitors ◽

Factor Ii ◽

Prevention And Treatment ◽

Faktor Xa ◽

Prävention Und Therapie

Download Full-text

Oral factor Xa inhibitors and risk of subdural hematoma

Neurology ◽

10.1212/wnl.0000000000009826 ◽

2020 ◽

Vol 95 (5) ◽

pp. e480-e487

Author(s):

Luciana Catanese ◽

John W. Eikelboom ◽

Jackie Bosch ◽

Olga Shestakovska ◽

Kelvin Ng ◽

...

Keyword(s):

Randomized Trials ◽

Meta Analysis ◽

Anticoagulation Therapy ◽

Factor Xa ◽

Factor Xa Inhibitors ◽

Randomized Controlled ◽

Important Complication ◽

Increased Risk ◽

The Mean

ObjectiveSubdural hematomas (SDHs) are an uncommon, but important, complication of anticoagulation therapy. We hypothesized that the risks of SDH would be similar during treatment with oral factor Xa inhibitors compared with aspirin.MethodsWe assessed the frequency and the effects of antithrombotic treatments on SDHs in the recent international Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) randomized trial comparing aspirin 100 mg daily, rivaroxaban 5 mg twice daily, and rivaroxaban 2.5 mg twice daily plus aspirin. A systematic review/meta-analysis of randomized trials comparing oral factor Xa inhibitors vs aspirin on SDH risk was undertaken.ResultsAmong 27,395 COMPASS participants, 28 patients with SDHs were identified (mean age 72 years). SDH-associated mortality was 7%. Incidence was 0.06 per 100 patient-years (11 SDH/17,492 years observation) during the mean 23-month follow-up among aspirin-assigned patients and did not differ significantly between treatments. Three additional randomized controlled trials including 16,177 participants reported a total of 14 SDHs with an incidence ranging from 0.06 to 0.1 per 100 patient-years. Factor Xa inhibitor use was not associated with an increased risk of SDH compared to aspirin (odds ratio, 0.97; 95% confidence interval, 0.52–1.81; I2 = 0%).ConclusionThe frequency of SDH was similar in all 3 treatment arms of the COMPASS trial. The COMPASS trial results markedly increase the available evidence from randomized comparisons of oral factor Xa inhibitors with aspirin regarding SDH. From available, albeit limited, evidence from 4 randomized trials, therapeutic dosages of factor Xa inhibitors do not appear to increase the risk of SDH compared with aspirin.Clinical trial identifier number:NCT01776424.

Download Full-text

B-PO05-141 ASSESSMENT OF CLOT KINETICS IN PATIENTS ON UNINTERRUPTED ORAL ANTICOAGULATION THERAPY WITH FACTOR XA INHIBITORS

Heart Rhythm ◽

10.1016/j.hrthm.2021.06.1060 ◽

2021 ◽

Vol 18 (8) ◽

pp. S429

Author(s):

Carola Gianni ◽

Domenico G. Della Rocca ◽

Chintan Trivedi ◽

Sanghamitra Mohanty ◽

Amin Al-Ahmad ◽

...

Keyword(s):

Oral Anticoagulation ◽

Anticoagulation Therapy ◽

Factor Xa ◽

Factor Xa Inhibitors ◽

Oral Anticoagulation Therapy

Download Full-text

Comparison of the Anticoagulant and Antithrombotic Effects of Synthetic Thrombin and Factor Xa Inhibitors

Thrombosis and Haemostasis ◽

10.1055/s-0038-1645198 ◽

1990 ◽

Vol 63 (02) ◽

pp. 220-223 ◽

Cited By ~ 19

Author(s):

J Hauptmann ◽

B Kaiser ◽

G Nowak ◽

J Stürzebecher ◽

F Markwardt

Keyword(s):

Factor Xa ◽

Thrombin Inhibitors ◽

Factor Xa Inhibitors ◽

Venous Stasis ◽

Clotting Time ◽

Thrombosis Model ◽

Activity Factor ◽

Antithrombotic Effects

SummaryThe anticoagulant effect of selected synthetic inhibitors of thrombin and factor Xa was studied in vitro in commonly used clotting assays. The concentrations of the compounds doubling the clotting time in the various assays were mainly dependent on their thrombin inhibitory activity. Factor Xa inhibitors were somewhat more effective in prolonging the prothrombin time compared to the activated partial thromboplastin time, whereas the opposite was true of thrombin inhibitors.In vivo, in a venous stasis thrombosis model and a thromboplastin-induced microthrombosis model in rats the thrombin inhibitors were effective antithrombotically whereas factor Xa inhibitors of numerically similar IQ value for the respective enzyme were not effective at equimolar dosageThe results are discussed in the light of the different prelequisiles and conditions for inhibition of thrombin and factor Xa in the course of blood clotting.

Download Full-text

Spectrophotometric Assays of Prothrombin in Plasma of Patients Using Oral Anticoagulants

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657025 ◽

1979 ◽

Vol 42 (04) ◽

pp. 1296-1305 ◽

Cited By ~ 29

Author(s):

R M Bertina ◽

W van der Marel-van Nieuwkoop ◽

E A Loeliger

Keyword(s):

Prothrombin Time ◽

Vitamin K ◽

Oral Anticoagulation ◽

Vitamin K Antagonists ◽

Oral Anticoagulants ◽

Factor Xa ◽

Factor V ◽

Anticoagulant Treatment ◽

Factor Ii ◽

K Deficiency

SummaryTwo spectrophotometric assays for prothrombin have been developed and compared with a one stage coagulant and an immunological assay. One of these assays (called the XAPC assay) uses a combination of factor Xa, phospholipid, Ca2+ and factor V as activator of prothrombin, and measures only normal prothrombin. The second (the ECAR assay) uses Echis carinatus venom as activator. This assay measures both normal prothrombin and PIVKA II (protein induced by vitamin K antagonists/absence). Combination of the results obtained by the XAPC and ECAR assays provides rapid and reliable information on the degree of “subcarboxylation” of prothrombin (oral anticoagulation, vitamin K deficiency).For patients on long term anticoagulant treatment the prothrombin time (Thrombotest) shows better correlation with the ratio prothrombin/prothrombin plus PIVKA II (XAPC/ ECAR) than with the factor II concentration. For patients starting the anticoagulant treatment there is no correlation between the Thrombotest time and the XAPC/ECAR ratio.It seems doubtful that (a) spectrophotometric factor II assay(s) will be as useful as the prothrombin time in the control of oral anticoagulation.

Download Full-text