Pharmacodynamic Model for Warfarin under Thrombo-test Monitoring

To determine a pharmacodynamic model for warfarin under thrombo-test (TT) monitoring, we examined the correlation between steady state TT values, warfarin dosage and serum concentration in patients receiving warfarin treatment. Based on the results, we developed a pharmacodynamic model relating TT values to free warfarin concentrations. We studied 19 cardiac patients receiving warfarin anticoagulant therapy in whom warfarin serum concentrations and TT values were considered to be in a steady state. While no correlation was observed between steady-state TT values and either warfarin dosage per kilogram body weight or total warfarin concentration, a significant negative correlation was observed between steady-state TT values and free warfarin concentrations (r=-0.561, p