• Class Ia antiarrythmics (eg quinidine, hydroquinidine, disopyramide). • Class III antiarrythmics (eg amiodarone, sotalol, dofetilide, ibutilide). • Some antipsychotics (eg thioridazine, chlorpromazine, levomepromazine, trifluoperazine, cyamemazine, sulpiride, sultopride, amisulpride, tiapride, pimozide, haloperidol, droperidol). • Others (eg bepridil, cisapride, diphemanil, erythromycin IV, halofantrin, mizolastin, pentamidine, terfenadine, vincamine IV).