Effective use of fondaparinux in patient with unresponsiveness to nadroparin

What is known and objective Fondaparinux exhibits a similar mechanism of action as LMWH. Since both of these drugs bind to antithrombin and increase its affinity to factor Xa, fondaparinux is not expected to be an effective alternative anticoagulant to LMWH in case of LMWH resistance. Case summary We report on a case of effective anticoagulation using fondaparinux following total unresponsiveness to high doses of nadroparin administered twice daily, as confirmed via repeated anti‐Xa measurements. The antithrombin levels were within the normal range. What is new and conclusion To the best of our knowledge, this is the first report of the effective use of fondaparinux in the case of unresponsiveness to LMWH. Fondaparinux exhibits a similar mechanism of action as LMWH, therefore it is not expected to be an effective alternative anticoagulant to LMWH in case of LMWH resistance. We report on a case of effective anticoagulation using fondaparinux following total unresponsiveness to high doses of nadroparin. To the best of our knowledge, this is the first time that effective anticoagulation was attained via the application of fondaparinux but not LMWH.