CC BY 4.0 · TH Open 2021; 05(01): e84-e88
DOI: 10.1055/s-0040-1721734
Original Article

Plasma Rivaroxaban Level to Identify Patients at Risk of Drug Overexposure: Is a Single Measurement of Drug Level Reliable?

Krishnan Shyamkumar
1   Population Health Research Institute, Hamilton, Ontario, Canada
,
Jack Hirsh
2   Division of Hematology and Thromboembolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
,
Vinai C. Bhagirath
1   Population Health Research Institute, Hamilton, Ontario, Canada
2   Division of Hematology and Thromboembolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
3   Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada
,
Jeffrey S. Ginsberg
2   Division of Hematology and Thromboembolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
,
John W. Eikelboom
1   Population Health Research Institute, Hamilton, Ontario, Canada
2   Division of Hematology and Thromboembolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
3   Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada
,
Noel C. Chan
1   Population Health Research Institute, Hamilton, Ontario, Canada
2   Division of Hematology and Thromboembolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
3   Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada
› Institutsangaben
Funding This study was funded by the Hamilton Health Sciences Corporation New Investigator Fund (grant no.: NIF-13332), a competitive peer-reviewed grant to support research by early career investigators in Hamilton, Ontario, Canada. The funder was not otherwise involved in the study.
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Abstract

Introduction Dose adjustment based on laboratory monitoring is not routinely recommended for patients treated with rivaroxaban but because an association has been reported between high drug level and bleeding, it would be of interest to know if measuring drug level once could identify patients at risk of bleeding who might benefit from a dose reduction.

Objective This study was aimed to investigate the reliability of a single measurement of rivaroxaban level to identify clinic patients with persistently high levels, defined as levels that remained in the upper quintile of drug-level distribution.

Methods In this prospective cohort study of 100 patients with atrial fibrillation or venous thromboembolism, peak and trough rivaroxaban levels were measured using the STA-Liquid Anti-Xa assay at baseline and after 2 months. Values of 395.8 and 60.2 ng/mL corresponded to the 80th percentile for peak and trough levels, respectively, and levels above these cut-offs were categorized as high for our analyses.

Results Among patients with a peak or trough level in the upper quintile at baseline, only 26.7% (95% confidence interval [CI]: 10.9–52.0%), and 13.3% (95% CI: 2.4–37.9%), respectively, remained above these thresholds.

Conclusion Our findings do not support the use of a single rivaroxaban level measurement to identify patients who would benefit from a dose reduction because such an approach is unable to reliably identify patients with high levels.

Authors' Contributions

N.C.C, J.H., J.S.G., and J.W.E. were involved in the conception and design of the project. K.S., N.C.C., and V.C.B. were involved in data analysis. All authors interpreted the data. K.S. prepared the initial version of the manuscript and interpretation. All authors contributed to the drafting and revising of the manuscript and approved the final version of the manuscript.




Publikationsverlauf

Eingereicht: 02. September 2020

Angenommen: 05. November 2020

Artikel online veröffentlicht:
25. Februar 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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