Tirofiban-induced severe thrombocytopenia

A 56-year-old man with acute myocardial infarction underwent coronary arteriongraphy and percutaneous coronary intervention(PCI)after receiving regular treatment with oral aspirin and clopidogrel for 2 months.His platelet count was 185×10~9/L before PCI.Unfractionated heparin was given during the operation and an continuousⅣinfusion of tirofiban[0.1μg/(kg·min)]was given for 36 hours via a micropump after PCI.About 12 hours after starting tirofiban,the patient presented with sporadic ecchymoses on both upper extremities and the platelet count decreased to 5×10~9/L.Tirofiban,aspirin,and clopidogrel were withdrawn immediately and dexamethasone was given.On day 4 after PCI,clopidogrel was given again.On day 5 after PCI,aspirin was resumed.On day 6 after PCI,his ecchymoses disappeared and the platelet count returned to normal level.The patient's severe thrombocytopenia was considered to be induced by tirofiban.