Increased risk of QT prolongation w/ medicinal products known to prolong the QT interval or able to induce Torsade de pointes eg, class IA (eg, quinidine, disopyramide) or class III (eg, amiodarone, sotalol, dofetilide, ibutilide) antiarrhythmic medicinal products, methadone, moxifloxacin, antipsychotics.