Q: 54 year old male developed life threatening GI bleeding after Fondaparinux (arixtra) administration post orthopedic surgery. FFP and pRBC is ordered and volume resuscitation started. What else can be done to counter effect of Fondaparinux (Arixtra)?




Answer: Recombinant Factor VIIa

Low-molecular-weight heparins are inhibitors of factor Xa, but have small therapeutic window and has the risk of bleeding. Fondaparinux has a long elimination half-life.

rFVIIa overcome the inhibition of thrombin generation and normalize the fondaparinux-induced prolongation of aPTT and PT. Sensitive thrombin-generation assays demonstrated the efficacy of rFVIIa in restoring impaired thrombin formation after fondaparinux administration. rFVIIa reverses not only the anticoagulant effect of fondaparinux but also the profibrinolytic effects of this agent, probably through activation of thrombin-activatable fibrinolysis inhibitor (TAFI).




Reference:

Ability of Recombinant Factor VIIa to Reverse the Anticoagulant Effect of the Pentasaccharide Fondaparinux in Healthy Volunteers - Circulation. 2002;106: 2550