Hemolytic uremic syndrome associated with clopidogrel: a case report.

Clopidogrel and ticlopidine are antiplatelet agents used in the treatment of patients with cerebrovascular and peripheral vascular disease and to reduce the risk for thrombosis in patients undergoing coronary artery stenting. Ticlopidine has been reported to have major hematologic adverse effects, including neutropenia and thrombotic thrombocytopenic purpura or hemolytic uremic syndrome (HUS). Clopidogrel, an analogue of ticlopidine, was developed because it did not show bone marrow toxic effects in either tissue culture or animal models. In human studies, to date, clopidogrel has been associated with a low incidence of severe neutropenia and no reported cases of thrombotic thrombocytopenic purpura or HUS. For these reasons, clopidogrel has been increasingly used in place of ticlopidine after coronary artery stenting. We report a case of clopidogrel-associated HUS. This observation implicates clopidogrel as a possible causative agent in HUS.