A structure-activity relationship study of a series of novel Na+ channel blockers, structurally related to N-[3-(2, 6-dimethyl-1-piperidinyl) propyl]-α-phenylbenzeneacetamide (1, PD85639) is described. The diphenylacetic acid portion of the molecule was left unchanged throughout the study, while structural features in the amine portion and the amide alkyl linkage of the molecule were modified. The compounds were tested for inhibition of ...