Fondaparinux for the Treatment of Heparin-Induced Thrombocytopenia (HIT)

A Phase II Trial Using Fondaparinux in Patients With Confirmed or Suspected Heparin-Induced Thrombocytopenia (HIT)

The purpose of this study is to determine how safe and effective fondaparinux is in treating patients with suspected or confirmed heparin-induced thrombocytopenia (HIT).

Currently, standard treatment of HIT involves the transition from a direct thrombin inhibitor (a type of anticoagulant or "blood thinner") to warfarin, a different type of anticoagulant. Direct thrombin inhibitors (DTIs) require IV administration and frequent blood draws for dose adjustments, which can lead to prolonged hospitalization. DTIs also affect blood test measurements, making it difficult to determine proper dosages of warfarin. Fondaparinux is a drug that is approved by the FDA for the treatment of blood clots in deep veins and in the lungs. Fondaparinux is not FDA approved for the treatment of HIT. However, an increasing number of doctors are using fondaparinux instead of DTIs to treat HIT. Although fondaparinux appears to be more convenient and predictable than DTI medications, more research is needed to support its use as a treatment for HIT.

heparin-induced thrombocytopenia, thrombocytopenia, HIT, thrombosis, blood clot, blood thinner, anticoagulant, heparin, warfarin, fondaparinux, Arixtra

Dosage form: subcutaneous injection; dosage: 7.5 to 10.0 mg; frequency and duration: daily until blood test results rule out confirmed HIT - for patients with confirmed HIT, continue daily until INR (blood clotting) measurement rises to at least 2

Dosage form: oral; dosage: 2.5 to 5.0 mg; frequency and duration: (for confirmed HIT only) once daily, to begin when blood platelet count reaches at least 100,000, and continue for approximately 4 weeks

Clinically significant bleed is defined as Hemodynamically Significant Bleeding or Requiring Blood Transfusions While Being Treated With Fondaparinux

Inclusion Criteria: high risk for HIT based on "Four Ts score" of 6 or more Exclusion Criteria: pulmonary emboli at the time of enrollment arterial thrombosis at the time of enrollment limb threatening phlegmasia cerulea dolens at the time of enrollment Calculated Creatinin Clearance less than 50 ml/hr platelet count less than 50 Weight less than 50 kg pregnancy allergy to fondaparinux bacterial endocarditis history of neuraxial anesthesia and post-operative indwelling epidural catheter active major bleeding (hemodynamically significant or requiring transfusions) inability to give informed consent