“…Similar to other drugs, amiodarone’s I hERG blocking potency is greater when the drug is tested on mammalian cell lines expressing hERG [11] , [12] , [13] , [14] , [15] . With mammalian expression systems, I hERG IC 50 values for amiodarone of between ∼26 and 300 nM were reported [12] , [13] , [14] , [16] , [17] and its metabolite desethyl-amiodarone (DEA) has been shown also to inhibit I hERG , with an IC 50 of ∼160 nM [14] . It is likely, therefore, that I hERG / I Kr blockade contributes to the acute clinical effects of amiodarone administration and that an inhibitory action of DEA additionally contributes to the chronic actions of the drug [14] .…”