Prevents clot formation

  • AT prevents the expansion of a formed thrombus (clot) and the formation of additional clots


Maintains hemostasis

  • AT plays a critical role in maintaining hemostasis
    • Binds irreversibly to thrombin and factor Xa, preventing the conversion of fibrinogen into fibrin1,2
    • Provides 80% of the natural anticoagulant effect against thrombin1,2


Enhances Heparin Effectiveness

  • AT is necessary for the anticoagulation effects of heparin3
  • Heparin is ineffective in the absence or near absence of AT3

Thrombate III® (antithrombin III [human]) is indicated for the treatment of patients with hereditary antithrombin deficiency in connection with surgical or obstetrical procedures or when they suffer from thromboembolism.

In clinical studies, the most common adverse events were dizziness, chest discomfort, nausea, and dysgeusia.

The anticoagulant effect of heparin is enhanced by concurrent treatment with Thrombate III in patients with hereditary AT-III deficiency. Thus, in order to avoid bleeding, reduced dosage of heparin is recommended during treatment with Thrombate III.

Thrombate III is made from human plasma. Plasma products carry a risk of transmitting infectious agents, such as viruses, and theoretically, the Creutzfeldt-Jakob disease (CJD) agent, despite steps designed to reduce this risk. No cases of transmission of viral disease or CJD have ever been identified for Thrombate III.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit, or call 1-800-FDA-1088.


  1. Maclean PS, Tait RC. Hereditary and acquired antithrombin deficiency: epidemiology, pathogenesis and treatment options. Drugs. 2007;67(10):1429-1440.
  2. Kottke-Marchant K, Duncan A. Antithrombin deficiency. Issues in laboratory diagnosis. Arch Pathol Lab Med. 2002;126:1326-1336.
  3. Thrombate III® (antithrombin III [human]) Prescribing Information. Grifols.