Agranulocytosis immediately after oral administration of cibenzoline and dabigatran in a patient with paroxysmal atrial fibrillation.

This case report describes agranulocytosis immediately after oral administration of cibenzoline and dabigatran in a 70-year-old woman with paroxysmal atrial fibrillation (AF). No blasts were found in peripheral blood and bone marrow, and the white blood cell count increased abruptly by intravenous administration of granulocyte colony-stimulation factor, suggesting an allergic response caused by cibenzoline or dabigatran, or both. Though antiarrhythmic drugs with anticoagulation therapy are commonly used to treat paroxysmal AF, caution has to be paid to drug-induced agranulocytosis.