Abstract
Ticagrelor is a new oral antiplatelet drug that has a strong proven benefit of reducing the rate of death from cardiovascular causes, myocardial infarction, and stroke compared with clopidogrel. Ticagrelor is widely used by patients with acute coronary syndrome. However, profound thrombocytopenia has never been previously reported in such patients. We herein present our experience with a case of profound thrombocytopenia after ticagrelor administration. No drug possibly associated with thrombocytopenia was concomitantly prescribed. The patient's platelet count recovered rapidly after ticagrelor and platelet transfusion were discontinued.