Effects of the oral, direct factor Xa inhibitor rivaroxaban on commonly used coagulation assays.

Research output: Contribution to journalArticle

Abstract

Introduction: Rivaroxaban is an oral direct factor Xa inhibitor developed for prophylaxis and treatment of thromboembolic disorders. Laboratory monitoring is not necessary but the dose dependent effects on common reagents and assay procedures are largely unknown. Objectives: To investigate the effect of rivaroxaban on commonly used coagulation assays. Material and Methods: Rivaroxaban was added to plasma from healthy subjects in the concentration range 0 -1000 μg/L and analyzed using different reagents for activated partial thromboplastin time (APTT), prothrombin time (PT), antithrombin, fibrinogen and activated protein C (APC) resistance assays. Results: At an expected peak concentration of rivaroxaban in clinical use, the APTTs were almost invariably prolonged but at lower concentrations the effect was weak. The concentration needed to double the APTT varied between 389 ±106 μg/L to 617 ±149 μg/L for different reagents. The PT assays showed a marked degree of difference. In general, the Quick PT type assays were more sensitive compared to the Owren type PT assays. The results from antithrombin assays were dependent on the type of reagent with the Xa-based assay being sensitive for rivaroxaban with an estimated increase of 0.09 IU/mL per 100 μg/L rivaroxaban. There were only minor effects on fibrinogen assays based on thrombin reagents. The APTT-based assay for APC resistance is affected in a dose dependent manner whereas an assay based on the activation of coagulation at the prothrombinase level was unaffected. Conclusions: Different assays, and even different reagents within an assay group, display variable effects by therapeutic concentrations of rivaroxaban.

Details

Authors
  • Andreas Hillarp
  • F Baghaei
  • I F Blixter
  • K M Gustafsson
  • L Stigendal
  • M Sten-Linder
  • Karin Strandberg
  • T L Lindahl
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cardiac and Cardiovascular Systems
Original languageEnglish
Pages (from-to)133-139
JournalJournal of Thrombosis and Haemostasis
Volume9
Publication statusPublished - 2011
Publication categoryResearch
Peer-reviewedYes