title: Fondaparinux for thromboembolic treatment and prophylaxis of heparin-induced thrombocytopenia.
abstract: OBJECTIVE
  To review literature evaluating the use of fondaparinux for thromboembolic treatment and prophylaxis in patients with heparin-induced thrombocytopenia (HIT).
  
  
  METHODS
  A MEDLINE search (1966-February 2006) was conducted using the search terms fondaparinux, heparin, low-molecular-weight heparin, and thrombocytopenia to identify English-language articles. Additional sources were identified from bibliographies of select articles and the manufacturer.
  
  
  RESULTS
  Fondaparinux, a pentasaccharide that selectively inhibits factor Xa, has been reported to have negligible or no cross-reactivity in vitro with HIT antibodies. Thromboembolic treatment and prophylaxis with fondaparinux in patients with HIT has been described. Three cases reported patients who were successfully treated for thromboembolic events with fondaparinux after developing HIT during therapy with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). Another report showed positive outcomes using fondaparinux for prophylaxis in a patient who had previously developed HIT after receiving UFH. Moreover, 2 case series, one using fondaparinux for prophylaxis in patients with a previous diagnosis of HIT and the other using fondaparinux for treatment in patients who developed HIT while receiving UFH or LMWH, reported normal platelet counts during fondaparinux treatment. Finally, results of a retrospective review demonstrated that fondaparinux prevented thromboembolic events or recurrent thrombocytopenia in patients with a prior HIT diagnosis.
  
  
  CONCLUSIONS
  Limited data support the use of fondaparinux for thromboembolic treatment or prophylaxis in patients with antibody assay-confirmed HIT who do not have a contraindication for fondaparinux use. Randomized controlled trials have not been published; therefore, questions remain regarding efficacy, safety, optimal doses, treatment duration, and incidence of thromboembolic events when fondaparinux is used in this setting. Prospective trials evaluating the efficacy and safety of fondaparinux in this patient population need to be conducted to answer these questions.
authors.affiliation: Virginia Commonwealth University Medical Center/Medical College of Virginia Hospitals, Richmond, 23298, USA. lefird@mcvh-vcu.edu
authors.forename: Leigh E
authors.initials: LE
authors.lastname: Efird
authors.forename: Denise R
authors.initials: DR
authors.lastname: Kockler
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D000077425:Fondaparinux; D006493:Heparin / Q000009:adverse effects; D006801:Humans; D011134:Polysaccharides / Q000627:therapeutic use*; D013921:Thrombocytopenia / Q000139:chemically induced / Q000188:drug therapy*; D013923:Thromboembolism / Q000188:drug therapy / Q000517:prevention & control
chemical_list: D000925:Anticoagulants; D011134:Polysaccharides; D006493:Heparin; D000077425:Fondaparinux