Assessment of the impact of rivaroxaban on coagulation assays: Laboratory recommendations for the monitoring of rivaroxaban and review of the literature

The laboratory and the direct oral anticoagulants

“…16,19 Between-reagent variability should be considered when interpreting results. 16,19,26,30 BLOOD, 16 MAY 2013 x VOLUME 121, NUMBER 20 THE LABORATORY AND THE DIRECT ORAL ANTICOAGULANTS 4033…”

“…c Although few data are available, it is possible that measurements of proteins C and S, performed with clotting techniques, 26 individual coagulation factors, 26,27 and the search for lupus anticoagulants, 28 may also be affected by DOAC.…”

Novel Oral Anticoagulants: Efficacy, Laboratory Measurement, and Approaches to Emergent Reversal

“…5,6 At present, no assays or calibration reagents are FDA approved for the measurement of the direct oral factor Xa inhibitors, although such reagents may be available to clinical laboratories on a research use only basis. While rivaroxaban and apixaban have been shown to affect routine coagulation tests, including the aPTT, activated clotting time, PT, and chromogenic antifactor Xa assay, 15,19 no therapeutic ranges exist, complicating the interpretation of the results of these tests. 19,20 Overall, studies using spiked plasma samples suggest using either the PT (for a qualitative assessment of direct oral factor Xa inhibitors) or the chromogenic anti-factor Xa assay (for a quantitative assessment of direct oral factor Xa inhibitors).…”

“…15, [19][20][21] The PT provides a relatively more sensitive assessment of rivaroxaban and apixaban than the aPTT or the activated clotting time.…”

“…15, 19 Authors of a study performed by the manufacturer of apixaban recommended the chromogenic anti-factor Xa assay for assessment of apixaban. 21 If the chromogenic anti-factor Xa assay is used, it is important to use the appropriate calibrator (and specifically not to use heparin calibrators).…”