fondaparinux [ Arixtra,Quixidar,Sanofi Synthelabo brand of fondaparinux sodium,Sanofi brand of fondaparinux sodium,fondaparinux sodium ] synthetic analog of the pentasaccharide sequence that mediates the interaction of HEPARIN with ANTITHROMBINS and inhibits FACTOR Xa; used for the for prevention of venous thromboembolism after surgery