Pharmacokinetics and pharmacodynamics of recombinant soluble thrombomodulin in disseminated intravascular coagulation patients with renal impairment

Recombinant human soluble thrombomodulin (TM-α) was recently developed as an anticoagulant for patients with disseminated intravascular coagulation (DIC). However, the pharmacokinetics and pharmacodynamics of TM-α in DIC patients with severe renal impairment have not yet been elucidated. We investigated the pharmacokinetics and pharmacodynamics of TM-α in DIC patients with severe renal impairment. Eleven DIC patients with the severe renal impairment (creatinine clearance (CLcr) <30 ml/min) and 10 DIC patients without severe renal impairment (CLcr ≥ 30 ml/min) were included in this study. In all patients, a dose of 380 U/kg of TM-α was administered during a 30 min infusion. Blood samples were taken before the start of the first TM-α administration, and at 0.5, 2, 4, 8, and 24 h after the start of administration. Although the clearance of TM-α in the patients with renal impairment was 80% of that in the patients without renal impairment, none of the pharmacokinetic values were significantly different between the groups. In the pharmacokinetic simulation, however, the trough levels of TM-α increased gradually in the patients with renal impairment when the same dose of TM-α was repeatedly administered. After the administration of TM-α, the prothrombinase activities in the patients in both groups were sufficiently inhibited during the observation period. Although the pharmacokinetic values in DIC patients with severe renal impairment were only slightly different from those in DIC patients without severe renal impairment, we need to pay attention to the elevation of the trough levels of TM-α when the same dose of TM-α is repeatedly administered

Massive amounts of tissue factor induce fibrinogenolysis without tissue hypoperfusion in rats

Trauma-induced tissue factor (TF) release into the systemic circulation is considered to play an important role in the development of disseminated intravascular coagulation (DIC) immediately after severe trauma. However, the relationship between TF and hyperfibrinolysis, especially fibrinogenolysis, has been unclear. A total of 18 rats were divided into three groups: (a) the control group was infused with normal saline; (b) the low-dose group was infused with 4 U/kg TF; and (c) the high-dose group was infused with 16 U/kg TF. Arterial blood was drawn immediately and 2 and 4 h after the start of TF infusion. At each sampling point, arterial blood gases, platelet counts, and coagulation variables were measured. The fibrinogen degradation products were evaluated by a Western blot analysis. Hypotension, hypoxemia, and lactic acidosis were not observed in any of the three groups. In proportion to the doses of TF, the platelet counts, coagulation, and fibrinolysis variables deteriorated in line with DIC. The alpha 2-plasmin inhibitor levels significantly decreased in the high-dose group compared with the other groups. The amounts of fibrinogen degradation products increased in proportion to the doses of TF. The plasmin-alpha 2-plasmin inhibitor complex level in the high-dose group increased more than that of the other groups. In conclusion, TF can induce DIC associated with fibrinolysis and fibrinogenolysis without tissue hypoperfusion. The decrease in the alpha 2-plasmin inhibitor level and the significant increase in the plasmin level may be the two main factors underlying the pathogenesis of hyperfibrin(ogen)olysis after TF administration