Fondaparinux (Arixtra(R)), a safe alternative for the treatment of patients with heparin-induced thrombocytopenia?

UNLABELLED: Fondaparinux, a pentasaccharide which selectively binds to antithrombin III, has negligible to no cross-reactivity with heparin-induced thrombocytopenia (HIT) antibodies in in vitro studies. The lack of cross-reactivity suggests a potential role in the management of HIT, and indeed, there are several such case reports and small studies. These published data have used both the prophylactic and weight-based treatment doses. However, due to the small possibility of developing HIT with thromboembolic complications while receiving fondaparinux, it is suggested that the appropriate weight-based treatment dose be used. In all these reports, fondaparinux provided adequate anticoagulation, prevented further thromboembolic events, and platelet counts returned to normal. However, there have been a couple of case reports on possible HIT or HIT-like syndrome secondary to fondaparinux use.

CONCLUSION: Fondaparinux is an attractive anticoagulant therapy in patients with HIT. There is still the need for larger randomized trials evaluating the true efficacy, appropriate dose, safe duration of treatment, and the true incidence of HIT associated with fondaparinux.