The present invention relates to pyrazinoylguanidine sodium channel blocker compounds represented by formula (I):as well as pharmaceutical compositions comprising the compounds and their use in promoting hydration of mucosal surfaces, restoring mucosal defense, and promoting mucus clearance, as well as methods of treatment for chronic bronchitis, cystic fibrosis, rhinosinusitis, nasal dehydration, asthma, ciliary dyskinesia, otitis media, chronic obstructive pulmonary disease, emphysema, and Sjögren's disease.
