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Updated: May 24, 2026

Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood
Published on: October 12, 2012
Evaluation of the prothrombin time for measuring rivaroxaban plasma concentrations using calibrators and controls:
Meyer Michel Samama1, Genevieve Contant, Theodore E Spiro
1Hôtel-Dieu University Hospital, Paris, France. meyermichel.samama@biomnis.com
Abstract:
This study evaluated the prothrombin time (PT) assay for the measurement of plasma concentrations of rivaroxaban using calibrators and controls. The intra- and interlaboratory precision of the measurement was investigated in a field trial involving 21 laboratories. Each laboratory was provided with rivaroxaban calibrators and control plasma samples containing different concentrations of rivaroxaban, and PT reagents. The evaluation was carried out over 2 consecutive weeks using centrally provided and local PT reagents. A calibration curve was produced each day (for inter-run precision), and day-to-day precision was evaluated by testing 3 control plasma samples. A large interlaboratory variation (in seconds) was observed with local PT reagents. The results were less variable when expressed as rivaroxaban concentrations (ng/mL) or when central PT reagent was used (STA Neoplastine CI Plus). The widely available PT assay, in conjunction with rivaroxaban calibrators, may be useful for the measurement of peak plasma levels of rivaroxaban.
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