- Treated with any of the following medications: Class Ia antiarrhythmic agents such as quinidine, disopyramide/Class III antiarrhythmic agents such as amiodarone, sotalol; Drugs like: beperidil, cisapride, sultopride, thioridazine, intravenous (IV) erythromycin, IV vincamine, halofantrine, pentamidine, or sparfloxacin.