<prompt> Sparfloxacin and astemizole can cause:Ventricular arrhythmiaMyopathyElectrolyte imbalanceNephropathy  <response>: Ans. A Ventricular arrhythmiaRef: KDT 8e p764Both sparfloxacin and astemizole blocks cardiac K channels in high concentration. This property may result in torsades de pointes polymorphic ventricular tachycardia.Other drugs causing torsades de pointes are:TerfenadineCisaprideZiprasidoneGrepafloxacin 