Development of new methodologies for the chromogenic estimation of betrixaban concentrations in plasma.

Results showed that the improvement of current chromogenic anti-Xa methodologies enhances the sensitivity of these assays to betrixaban but also to indirect factor Xa inhibitors. This lack of specificity may lead to overestimation of betrixaban concentrations in patients bridged with heparins. To avoid this cross-interference, the use of the Biophen® DiXaI® may be a solution except for fondaparinux which remains active even in the presence of the Biophen® DiXaI® 's specific buffer. For the other chromogenic assays, the conception and validation of specific buffer is required.