As a consequence, the use of sparfloxacin in patients with known Q-Tc prolongation congenital or acquired (e. g. acute myocardial infarction) and the concomitant use of drugs known to produce an increase in the Q-Tc interval and/ or torsades de pointes is inadvisable: e. g. quinine, chloroquine, erythromycin, terfenadine, astemizole, probucol, halofantrine, pentamidine, vincamine, class Ia antiarrhythmic agents (e. g. quinidine, procainamide, disopyramide), class III anti-arrhythmic agents (e. g. bretylium), some tricyclic antidepressants, some neuroleptics (e. g. sultopride, phenothiazines) (see “ Interaction with other medicinal products and other forms of interaction”).