An Nav1.7 channel blocker (IC50s = 11, 16, 33, and 20 nM for 5N11S, 5A11L, 5A11S, and 5A11L Nav1.7 splice variants, respectively); selective for Nav1.7 over Nav1.1-1.6 and 1.8 channels (IC50s = 0.11-25 μM), L-type calcium, and KvLQT and hERG potassium channels (IC50s = ≥10 μM), as well as human and cynomolgus monkey TRPV1 receptors (IC50s = 10 and 20 μM); 1,000-fold selective for half-inactivated over resting Nav1.7 channels; mutation of VSD4 reduces potency by ~100-fold