Drug-induced Thrombocytopenia After Anticoagulation with Rivaroxaban

A 66-year-old man presented to the emergency department with complaints of dark-colored stool and rash developing over the last couple of days. The patient was started on rivaroxaban and flecainide for months prior for atrial fibrillation. Upon arrival, he was awake, alert, and oriented with a blood pressure of 111/63mmHg, heart rate of 68 beats per minute, and oxygen saturation of 96% on room air. A review of systems was unremarkable with the exception of skin rash and light-headedness. The patient's initial laboratory results were significant for red blood cell (RBC) count of 4.05×10/mcL, hemoglobin of 12.1g/dL, hematocrit of 35.6%, and platelet count of 1×103/mcL. Aggressive hydration was started in the ED, initially with two 1-L boluses of normal saline followed by an infusion of 10mL/h. One unit of platelets was transfused. Rivaroxaban and flecainide were held on admission. Twenty-four hours after admission, the patient was initiated on immune globulin (IVIG) Gammagard (Baxter, West Lake, CA), 75g on 3 consecutive days and steroids for possible immune thrombocytopenia. His platelet count steadily improved over the 6-day period to 119×103/mcL on the day of hospital discharge. This is the second reported case of possible rivaroxaban-induced thrombocytopenia.