Last reviewed 2026-04-23 · How we verify

Human plasma derived antithrombin

Antithrombin is a natural anticoagulant protein that inhibits blood clotting factors to prevent thrombosis.

Antithrombin is a natural anticoagulant protein that inhibits blood clotting factors to prevent thrombosis. Used for Antithrombin deficiency (congenital or acquired), Thromboembolism prevention and treatment in high-risk patients.

At a glance

Mechanism of action

Antithrombin is a serine protease inhibitor that binds to and inactivates thrombin (Factor IIa) and other activated coagulation factors (particularly Factor Xa). By neutralizing these key enzymes in the coagulation cascade, antithrombin prevents the formation of blood clots and is used therapeutically in patients with antithrombin deficiency or thrombotic disorders.

Approved indications

• Antithrombin deficiency (congenital or acquired)
• Thromboembolism prevention and treatment in high-risk patients

Common side effects

• Injection site reactions
• Headache
• Dizziness
• Nausea
• Fever

Key clinical trials

• Phase 3 Study on the Efficacy and Safety of Human Plasma Derived Antithrombin (Atenativ) in Heparin-Resistant Patients Scheduled to Undergo Cardiac Surgery Necessitating Cardiopulmonary Bypass (PHASE3)
• Antithrombin III in Infants With Cardiopulmonary Bypass (CPB) (PHASE1)

Primary sources

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