3,5-diamino-6-chloro-N-(N-(4-phenylbutyl)carbamimidoyl) pyrazine-2-carboxamide compounds

A method for blocking sodium channels in a subject or a cell comprising administering to the subject or cell a compound of the formula:

• or a pharmaceutically acceptable salt thereof, wherein:
• Ar is a moiety selected from the group of:
• X is selected from —CH2—, —O—, and —S—;
• R1 and R2 are independently selected from H and C1-C6 alkyl;
• or R1 and R2 together with the nitrogen atom to which they are bound form a 5-membered or 6-membered heterocyclic ring optionally containing one additional ring heteroatom selected from N and O;
• R3 is an alkyl group having from 3 to 8 carbon atoms or a polyhydroxylated alkyl group having from 3 to 8 carbon atoms;
• R4 is a polyhydroxylated alkyl group having from 3 to 8 carbon atoms;
• and
• R5 is selected from H and C1-C3 alkyl.