Laboratory testing of rivaroxaban in routine clinical practice: When, how, and which assays

Abstract

A number of target-specific oral anticoagulants (TSOAs) have been developed in recent years, and some have shown considerable promise in large-scale, randomized clinical trials in the prevention and treatment of thromboembolism. Unlike traditional anticoagulants, such as vitamin K antagonists, these TSOAs exhibit predictable pharmacokinetics and pharmacodynamics. Among these agents, rivaroxaban, a direct Factor Xa inhibitor, has been approved for clinical use in many countries for the management of several thromboembolic disorders. As with the other TSOAs, rivaroxaban is given at fixed doses without routine coagulation monitoring. However, in certain patient populations or special clinical circumstances, measurement of drug exposure may be useful, such as in suspected overdose, in patients with a haemorrhagic or thromboembolic event during treatment with an anticoagulant, in those with acute renal failure, or in patients who require urgent surgery. This article summarizes the influence of rivaroxaban on commonly used coagulation assays and provides practical guidance on laboratory testing of rivaroxaban in routine practice. Both quantitative measurement (using the anti-Factor Xa method) and qualitative measurement (using prothrombin time, expressed in seconds) are discussed, together with some practical considerations when performing these tests and interpreting the test results.

Key words::

• Anticoagulants
• laboratory testing
• rivaroxaban

Acknowledgements

The authors would like to acknowledge Yong-Ling Liu, who provided editorial support with funding from Bayer HealthCare Pharmaceuticals and Janssen Scientific Affairs, LLC.

Declaration of interest: E. Lindhoff-Last has acted as a consultant and is a member of the national advisory board of Bayer Schering Pharma AG, Boehringer Ingelheim, Daiichi Sankyo; a consultant for Pfizer and a consultant and member of the international advisory board of Instrumentation Laboratory. J. Ansell is a consultant for Bristol-Myers Squibb, Pfizer, Boehringer Ingelheim, Janssen, and Daiichi and serves on the Data Safety Monitoring Board of Bristol-Myers Squibb. T. Spiro is an employee of Bayer HealthCare Pharmaceuticals Inc. M. M. Samama is a consultant for Bayer, sanofi-aventis, Eli Lilly, and Daiichi Sankyo, and is a member of an advisory committee of Johnson & Johnson and Pfizer.