A cyclohepta[b]pyridine-3-carbonylguanidine compound represented by Formula (1): wherein R1 represents a group selected from a sulfo group, a sulfoxy group, -OCONH-(CH2CH2OVSO3H and the following formulas: R2 represents a halogen atom, a lower alkyl group or a lower alkoxy group and n represents an integer from 1 to 10, or a pharmaceutically acceptable salt thereof.