The present application provides sodium channel blockers exemplified by the following structure: The compounds of the invention useful for treating chronic bronchitis, cystic fibrosis, sinusitis, vaginal dryness, dry eye, Sjogren's disease, distal intestinal obstruction syndrome, dry skin, esophagitis, dry mouth (xerostomia), nasal dehydration, ventilator-induced pneumonia, asthma, primary ciliary dyskinesia, otitis media, chronic obstructive pulmonary disease, emphysema, pneumonia, constipation, and chronic diverticulitis, for example.