1-Benzazepin-2-one Nav1 inhibitors. The structures of two 1-benzazepin-2-one Nav1 inhibitors are illustrated together with their potencies for hNav1.5, hNav1.7, and hNav1.8 channels as determined in functional membrane potential, FRET-based assays. The estimated potencies of these compounds for the inactivated state of hNav1.5 and hNav1.7 channels, as determined from electrophysiological recordings, are also presented. Note that only compound 2 displays selectivity for the hNav1.7 channel. Both compounds are weaker inhibitors of the hNav1.8 channel.