Hematologic Adverse Effects of Clopidogrel

Clopidogrel is used as a frontline antiplatelet agent in patients with coronary artery disease, cerebrovascular disease, and peripheral vascular disease. Hematologic complications and bleeding have been the most feared outcome of antithrombotic and antiplatelet agents. Among the thienopyridines, clopidogrel is considered to be a safer alternative to ticlopidine due to its decreased incidence of hematologic adverse effects. Although thrombotic thrombocytopenia purpura is the most reported hematologic adverse effect of clopidogrel; neutropenia, acquired hemophilia, isolated thrombocytopenia or idiopathic immune thrombocytopenia, and thrombotic thrombocytopenia purpura with hemolytic uremic syndrome are other rare yet recognized hematologic adverse effects of clopidogrel. Patients treated with clopidogrel should be carefully monitored for hematologic adverse effects especially in the first 2 to 3 months after initiation of therapy. Early recognition and prompt initiation of treatment can be life saving in patients who have hematologic adverse effects to clopidogrel. We have drafted this review by performing literature search using Medline, Pubmed, and EMBASE search engine with relevant search words for all reported hematologic adverse effects and manifestations of clopidogrel and their management.