Antithrombin Deficiency Treatment & Management

Updated: Oct 21, 2015
  • Author: Bryan A Mitton, MD, PhD; Chief Editor: Perumal Thiagarajan, MD  more...
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Approach Considerations

In patients with a known inherited antithrombin (AT) deficiency, management of an acute thrombotic event becomes challenging, as these patients may exhibit a variable response to even large doses of heparin. When a therapeutic response to intravenous heparin is not achievable, additional support with an antithrombin concentrate may be necessary. [46]

Low molecular weight heparins (LMWHs) nor factor Xa inhibitors (eg, fondaparinux) may also be unreliable in this setting. Those agents also require antithrombin for their antithrombotic action.

Patients with known antithrombin deficiency should be considered candidates for antithrombotic prophylaxis during high-risk situations such as surgery and pregnancy.

Alternatives to heparin include synthetic direct thrombin inhibitors that do not require antithrombin for their anticoagulant effect (eg, argatroban). Such inhibitors are also more desirable because they may avoid exposure to biologic products such as plasma or antithrombin concentrate, which are currently required for the adequate anticoagulant action of presently available agents.


Correction of Antithrombin Levels

For a planned major operation, correction of antithrombin levels using antithrombin concentrate products is recommended in patients with known antithrombin (AT) deficiency. In acute severe trauma, some studies also suggest a beneficial effect with antithrombin replacement.

In contrast to antithrombin concentrates, fresh frozen plasma (FFP) does not have a sufficient concentration of antithrombin to provide adequate replacement in patients who are significantly deficient, so FFP should not be used if alternatives are available. The goal of correction should be to antithrombin activity of 80% or greater, to achieve physiologic function.



See the list below:

  • Close consultation with a hematologist is necessary.
  • Obtain consultation with a geneticist as needed.
  • The support of a laboratory equipped to assay antithrombin activity is necessary in patients receiving antithrombin replacement therapy.