darexaban and Thrombosis

Insomnia is an important adverse event of mechanical thromboprophylaxis. This sleep disorder has been reported as one of the commonest adverse events of the new oral anti-Xa anticoagulant darexaban, with similar rates to mechanical thromboprophylaxis in a randomized controlled trial (RCT). However, the perceived effect could have been biased because it was an open-label RCT. Therefore, we aimed to review the incidence of insomnia with non-vitamin K antagonist oral anticoagulants (NOACs).. We performed a systematic review and meta-analysis of Phase III RCTs. Electronic databases MEDLINE and CENTRAL (inception to September 2013) were searched as well as review articles and references of included studies. We included phase III RCTs which compared NOACs with any other control group. Data were analyzed and pooled to estimate risk ratio (RR) with 95% confidence intervals (95%CI) for insomnia using inverse variance method. Statistical heterogeneity was evaluated with I(2) test.. We included seven studies (two apixaban RCTs, two dabigatran RCTs, one darexaban RCTs, and two rivaroxaban RCTs), enrolling a total of 23,023 patients. Overall, NOACs were not associated to an increased risk of insomnia: RR 0.94 (95%CI 0.83-1.08; I(2) = 0%). In blinded studies (six studies), NOACs also did not show increased risk of insomnia (RR 0.94, 95%CI 0.83-1.08; I(2) = 0%). Results were similar irrespective of the comparators.. NOACs (apixaban, dabigatran, darexaban, rivaroxaban) did not show increased risk of insomnia. Results according to study design (blinded vs. open-label trials) overlap the main analysis.

Topics: Administration, Oral; Anticoagulants; Azepines; Benzamides; Clinical Trials, Phase III as Topic; Humans; Randomized Controlled Trials as Topic; Sleep Initiation and Maintenance Disorders; Thrombosis; Vitamin K

Here, we investigated the anticoagulant effects of darexaban in mice and human plasma in vitro, effects of darexaban in thrombosis and bleeding models in mice, and reversal effects of anti-inhibitor coagulant complex (ACC) and recombinant factor VIIa (rFVIIa) on anticoagulant effects of darexaban. In mice, darexaban inhibited FXa activity in plasma with an ED50 value of 24.8 mg/kg. Both darexaban and warfarin prolonged prothrombin time (PT) at 3 mg/kg and 0.3 mg/kg/day, respectively. PT and activated partial thromboplastin time (aPTT) prolonged by darexaban were dose-dependently reversed by intravenously-administered rFVIIa, significantly so at 1 mg/kg. In a pulmonary thromboembolism (PE) mouse model, both darexaban and warfarin dose-dependently reduced the mortality rate, significantly so at 10 mg/kg and 3 mg/kg/day, respectively. In a FeCl3-induced venous thrombosis (VT) mouse model, darexaban (0.3-10 mg/kg) dose-dependently decreased the thrombus protein content, significantly so at doses of 3 mg/kg or higher. In a tail-transection mouse model, darexaban had no significant effect on the amount of blood loss at doses up to 10 mg/kg, while warfarin showed a dose-dependent increase in blood loss, significantly so from 1 mg/kg/day. Darexaban and its metabolite darexaban glucuronide significantly prolonged PT and aPTT in human plasma in vitro, and while rFVIIa concentration-dependently reversed the prolonged PT in this plasma, ACC dose-dependently reversed both PT and aPTT changes prolonged by darexaban. Taken together, these results suggest that darexaban has a potential to be an oral anticoagulant with a better safety profile than warfarin, and that rFVIIa and ACC may be useful as antidotes to darexaban in cases of overdose.

Topics: Animals; Anticoagulants; Azepines; Benzamides; Disease Models, Animal; Factor VIIa; Hemorrhage; Humans; Male; Mice; Mice, Inbred ICR; Partial Thromboplastin Time; Prothrombin Time; Recombinant Proteins; Thrombosis; Warfarin

We evaluated the relationship between antithrombotic effects and pharmacodynamic (PD) marker changes produced by the novel factor (F)Xa inhibitors darexaban (YM150) and rivaroxaban in a rabbit model of plaque disruption-induced arterial thrombosis. Animals were subjected to catheter-induced endothelial denudation via the femoral artery followed by a two-week high-cholesterol diet. Plaque disruption was induced by balloon angioplasty, and then stasis was achieved by ligation at the distal side of the injured segment. Darexaban and rivaroxaban were administered orally 1 hour (h) before and 9 h after plaque disruption, and their antithrombotic effects were evaluated 24 h after the initiation of ligation. Prothrombin time (PT), activated partial thromboplastin time (APTT), and plasma FXa activity were measured using blood samples collected before and 1h after administration. Darexaban and rivaroxaban significantly reduced thrombus formation. The thrombus weight obtained in the 30 mg/kg darexaban group was comparable to that in the 1 mg/kg rivaroxaban group (2.17 ± 0.63 and 3.23 ± 1.64 mg, respectively, vs. 8.01 ± 1.08 mg in the control group). Plasma FXa activity correlated with the antithrombotic effects of darexaban and rivaroxaban, while PT only correlated with those of darexaban. Our findings suggest that the degree of plasma FXa inhibition may be useful for predicting antithrombotic effects of darexaban and rivaroxaban in arterial thrombosis. PT may also be useful in evaluating antithrombotic effects of darexaban in particular.

Topics: Administration, Oral; Animals; Anticoagulants; Azepines; Benzamides; Disease Models, Animal; Factor Xa Inhibitors; Femoral Artery; Lipids; Male; Morpholines; Plaque, Atherosclerotic; Prothrombin Time; Rabbits; Rivaroxaban; Thiophenes; Thrombosis

Darexaban (YM150) is an oral factor Xa inhibitor developed for the prophylaxis of venous and arterial thromboembolic disease. This study was conducted to investigate the biochemical and pharmacological profiles of darexaban and its active metabolite darexaban glucuronide (YM-222714), which predominantly determines the antithrombotic effect after oral administration of darexaban. In vitro activity was evaluated by enzyme and coagulation assays, and a prothrombin activation assay using reconstituted prothrombinase or whole blood clot. In vivo effects were examined in venous thrombosis, arterio-venous (A-V) shunt thrombosis, and bleeding models in rats. Both darexaban and darexaban glucuronide competitively and selectively inhibited human factor Xa with Ki values of 0.031 and 0.020 μM, respectively. They showed anticoagulant activity in human plasma, with doubling concentrations of darexaban and darexaban glucuronide for prothrombin time of 1.2 and 0.95 μM, respectively. Anticoagulant activity was independent of antithrombin. Darexaban and darexaban glucuronide inhibited the prothrombin activation induced by prothrombinase complex or whole blood clot with similar potency to free factor Xa. In contrast, prothrombinase- and clot-induced prothrombin activation were resistant to inhibition by enoxaparin. In venous and A-V shunt thrombosis models in rats, darexaban strongly suppressed thrombus formation without affecting bleeding time, with ID₅₀ values of 0.97 and 16.7 mg/kg, respectively. Warfarin also suppressed thrombus formation in these models, but caused a marked prolongation of bleeding time at antithrombotic dose. In conclusion, darexaban is a selective and direct factor Xa inhibitor and a promising oral anticoagulant for the prophylaxis and treatment of thromboembolic diseases.

Topics: Administration, Oral; Animals; Anticoagulants; Azepines; Benzamides; Bleeding Time; Disease Models, Animal; Dogs; Dose-Response Relationship, Drug; Enoxaparin; Factor Xa Inhibitors; Glucuronides; Humans; Macaca fascicularis; Male; Mice; Mice, Inbred ICR; Prothrombin Time; Rabbits; Rats; Rats, Sprague-Dawley; Thrombosis; Venous Thrombosis; Warfarin