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Open Access
CC BY 4.0 · TH Open 2021; 05(03): e353-e362
DOI: 10.1055/s-0041-1731777
Review Article

The Importance of Appropriate Dosing of Nonvitamin K Antagonist Oral Anticoagulants for Stroke Prevention in Patients with Atrial Fibrillation

Authors

  • Jan Beyer-Westendorf

    1   Thrombosis Research Unit, Division Hematology, Department of Medicine I, University Hospital “Carl Gustav Carus” Dresden, Dresden, Germany
    2   Department of Haematology, Kings Thrombosis Service, Kings College London, United Kingdom

  • Matthew Fay

    3   Westcliffe Medical Practice, Westcliffe Road, Shipley, United Kingdom

  • Walid Amara

    4   Groupe Hospitalier Intercommunal Le Raincy-Montfermeil, Montfermeil, France
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Abstract

Preventing thromboembolic events, while minimizing bleeding risks, remains challenging when managing patients with atrial fibrillation (AF). Several factors contribute to current dosing patterns of nonvitamin K antagonist oral anticoagulants (NOACs), including patient characteristics, comorbidities, and physician judgment. Application of NOAC doses inconsistent with the drug labels may cause patients to receive either subtherapeutic (increasing stroke risk) or supratherapeutic (increasing bleeding risk) anticoagulant levels. In clinical practice, under- or over-dosing of NOACs in patients with AF is not uncommon. This analysis of prospective and retrospective registry and database studies on NOAC use in patients with AF (with at least 250 patients in each treatment arm) showed that under-dosing may be associated with reduced effectiveness for stroke prevention, with similar or even increased bleeding than with the standard dose. This may reflect underlying conditions and patient factors that increase bleeding despite NOAC dose reduction. Such factors could drive the observed overuse of reduced NOAC dosages, often making the prescription of reduced-dose NOAC an intentional label deviation. In contrast, over-dosing more likely occurs accidentally; instead of providing benefits, it may be associated with worse safety outcomes than the standard dose, including increased bleeding risk and higher all-cause mortality rates. This review summarizes the main findings on NOAC doses usually prescribed to patients with AF in clinical practice.

Keywords

anticoagulants - atrial fibrillation - stroke

Note

The authors take responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation.




Publication History

Received: 03 November 2020

Accepted: 22 April 2021

Article published online:
23 August 2021

© 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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