Fondaparinux binder ikke til trombocytfaktor 4, og giver ikke krydsreaktion med sera fra patienter med heparin- induceret trombocytopeni type II (HIT II).
Fondaparinux does not bind to platelet factor 4 and does not cross-react with sera from patients with Heparin Induced Thrombocytopenia (HIT) type II.