Provided is a therapeutic and/or prophylactic agent for respiratory diseases, or a therapeutic and/or prophylactic agent for sodium channel-mediated diseases.A pharmaceutical agent which contains, as an active ingredient, a compound represented by formula (I) or a pharmacologically acceptable salt thereof.In formula (I), each of Ar1 and Ar2 represents a heteroaryl group or an aryl group each of R1, R2 and R3 represents a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a halogenated C1-C6 alkyl group, a hydroxy C1-C6 alkyl group, a C1-C6 alkoxy C1-C6 alkyl group, a C3-C7 cycloalkyl group or a cyano group each of R4 and R5 represents a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a halogenated C1-C6 alkyl group, a hydroxyl group, a hydroxy C1-C6 alkyl group, a C1-C6 alkoxy C1-C6 alkyl group, a C3-C7 cycloalkyl group or a C1-C6 alkoxy group and n represents an integer of 1-3. In this connection, the heteroaryl group and the aryl group may have one or two groups that are independently selected from among a halogen atom, a C1-C6 alkyl group, a halogenated C1-C6 alkyl group, a hydroxyl group, a hydroxy C1-C6 alkyl group, a C1-C6 alkoxy C1-C6 alkyl group, a C3-C7 cycloalkyl group, a carboxyl group, a cyano group, an amino group, a C1-C3 alkylamino group and a di C1-C3 alkylamino group, and in cases where two groups are contained therein, the groups may be the same as or different from each other.La présente invention concerne un agent thérapeutique et/ou prophylactique pour des maladies respiratoires, ou un agent thérapeutique et/ou un agent prophylactique pour les maladies médiées par les canaux sodiques.La présente invention concerne par conséquent un agent pharmaceutique qui contient, en tant quingrédient actif, un composé représenté par la formule (I) ou un sel pharmacologiquement acceptable de celui-ci.Dans la formule (I), chacun de Ar1 et Ar2 représente un groupe hétéroaryle ou un groupe aryle chacun de R1, R2 et R3 représente un atome dhydrogène, un atom
