Characterization of anticoagulation by dabigatran and rivaroxaban. (A-B) aPTT (A) and plasma concentration (B) of dabigatran (active compound) in mice fed for 4 days with chow containing placebo or different amounts of inactive dabigatran (n = 3-5 per group). The overall P value from a 1-way ANOVA is P < .0001). (C-D) PT (seconds) (C) and plasma concentration (D) of rivaroxaban in mice fed for 10 days with chow containing placebo or different amounts of rivaroxaban (n = 5 per group). The overall P value from a 1-way ANOVA is P = .0134. (E-F) Hemostasis time (E) and the number of disruptions (F) in WT mice fed with chow containing placebo (n = 6), rivaroxaban (0.4 mg/g chow; n = 6), or dabigatran (10 mg/g chow; n = 5) for 5 days. Bleeding was observed for 30 minutes, and any formed clots were disrupted. Average bleeding time was calculated from the individual bleeding times determined during the 30-minute period; the number of clots formed is also reported (disruption number). Asterisks directly above the bars indicate the statistical significance of dabigatran- or rivaroxaban-treated mice compared with placebo-treated mice (*P < .05, **P < .01, and ***P < .001). Dab, dabigatran; Con, control placebo; Riv, rivaroxaban.