ATENATIV Powder and solvent for solution for infusion Ref.[4776] Active ingredients: Antithrombin III

Pharmacotherapeutic Group: Antithrombotic agents, heparin group
ATC Code: B01AB02

Antithrombin, a 58 kD, 432 amino-acid glycoprotein, belongs to the serpin (serin protease inhibitor) superfamily. It is one of the most important natural inhibitors of blood coagulation. The factors most strongly inhibited are thrombin and factor Xa, but also factors of contact activation, intrinsic system and the factor VIIa/tissue factor complex. Antithrombin activity is greatly enhanced by heparin and the anticoagulant effects of heparin depend on the presence of antithrombin. Antithrombin contains two functionally important domains. The first contains the reactive centre and provides a cleavage site for proteinases such as thrombin, a prerequisite for forming a stable proteinase-inhibitor complex. The second is a glycosaminoglycan binding domain responsible for the interaction with heparin and related substances, which accelerates the inhibition of thrombin. The inhibitor-coagulation enzyme complexes are removed by the reticulo-endothelial system. Antithrombin activity in adults is 80-120% and levels in neonates are about 40-60%.

Antithrombin should be administered restrictively in connection with acquired antithrombin deficiency and in consultation with a coagulation specialist. There are several smaller studies of consumption syndrom (DIC), sepsis, preeclampsia, L-asparaginase treatment of acute lymphoblastic leukaemia, veno-occlusive disease, surgery with heart-lung machine, where antithrombin administration has shown positive effects on coagulation parameters. Convincing effects on morbidity and mortality has not been documented in these occasions. In the so called Kybersept study, which included more than 2300 patients with sepsis, there was no difference in mortality in those treated with antithrombin compared to placebo.