Donepezil-induced torsades de pointes without QT prolongation.

We report a case of torsades de pointes (TdP) induced by donepezil without QT prolongation. An 86-year-old woman was admitted to our hospital because of a syncopal attack. She had been treated for Alzheimer's disease with donepezil. Initial 12-lead electrocardiogram showed atrial fibrillation and normal corrected QT interval. After admission, atrial fibrillation spontaneously recovered to normal sinus rhythm on electrocardiographic monitoring. On the second day, electrocardiographic monitoring documented TdP. We discontinued donepezil immediately. After washout of donepezil, TdP was not observed again. Corrected QT interval was normal throughout hospitalization. This case suggests that donepezil may cause life-threatening ventricular arrhythmias without QT prolongation. Even if corrected QT interval is normal in patients taking donepezil and experiencing symptoms associated with TdP, electrocardiographic monitoring is recommended. <Learning objective: Donepezil may cause life-threatening ventricular arrhythmias without QT prolongation. Even if corrected QT interval is normal in patients taking donepezil and experiencing symptoms associated with torsades de pointes, electrocardiographic monitoring is recommended.>.