Often used as disinfectants, quaternary-ammonium compounds (qac) displaying one positively charged Nitrogen atom (N + ) at their centre, strongly inhibit K + channel flows by competing with the channel K + -binding selectivity filters . Symmetrical alkyl-chain qac derivatives of different lengths (i.e, tetraethylammonium) discovered additional hydrophobic cavities for binding which extended the central qac-binding cavity towards the four monomeric interfaces . Alkyl-qac binds both to the channel internal hydrophilic cavities below the K + selectivity filters such as 100 I and 103 F amino acid side chains stabilizing qac binding 13, 14 17 , increasing K + loss, and inactivating ion channels. These results suggested that non-toxic qac alternatives (i.e., other hydrophilic heads and/or other hydrophobic alkyl chains) might predict higher affinities and more potent inhibitors..