Isolated profound thrombocytopenia associated with clopidogrel.

Clopidogrel is a new oral antiplatelet agent with a structure and mechanism of action similar to ticlopidine; they both block the adenosine diphosphate receptor. Because of better side-effect profile and simpler dosing regime, clopidogrel has largely replaced ticlopidine. In fact, the excellent safety and tolerability profile of clopidogrel compares favorably with that of aspirin as documented in the CAPRIE (Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events) study. After marketing, several cases of clopidogrel-associated thrombotic thrombocytopenic purpura (TTP) were reported. We report our experience with a case of isolated profound thrombocytopenia without evidence of TTP after clopidogrel administration with prompt recovery of platelet counts upon discontinuation of clopidogrel and treatment with intravenous immunoglobulin.