Hypersensitivity. Known QT-interval prolongation; congenital long QT syndrome; recent acute MI; uncompensated heart failure; arrhythmias treated w/ class IA & III antiarrhythmic medicinal products. Concomitant treatment w/ medicinal products that prolong the QT interval eg, class IA & III antiarrhythmics, arsenic trioxide, halofantrine, levomethadyl acetate, mesoridazine, thioridazine, pimozide, sparfloxacin, gatifloxacin, moxifloxacin, dolasetron mesilate, mefloquine, sertindole or cisapride.