The International Normalized Ratio calibrated for rivaroxaban has the potential to normalize prothrombin time results for rivaroxaban-treated patients: results of an in vitro study.

摘要

Millions of patients are involved worldwide in the treatment/ prevention of thromboembolic diseases with vitamin K antagonists (VKAs), heparins or congeners. In the next few years, many of these patients will presumably be switched to the new antithrombotics, such as rivaroxaban. Apparently, this drug does not require laboratory monitoring for dose adjustment, because of its predictable pharmacokinetics/pharmacodynarn-ics [1]. However, the measurement of its pharmacologic effect might be of value in selected patients, such as those with renal failure [2]. Furthermore, laboratory monitoring might help in checking patient compliance or in revealing over-anticoagula-tion [2]. Because of its simplicity and availability, the prothrombin time (PT) could be a good candidate. A recent study [3] investigated its suitability using normal plasma spiked with increased concentrations of rivaroxaban, chosen to mimic plasma levels (up to 1.00mg mL~(-1)) in excess of those that would be obtained after administration of oral doses of 10 mg or more once-daily or twice-daily [1].