The present invention provides an agent for preventing or treating neuropathy having superior action and low toxicity. This agent comprises a compound represented by the formula: wherein ring A is a 5-membered aromatic heterocycle containing 2 or more nitrogen atoms, which may further have substituent(s); B is an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group; X is a divalent acyclic hydrocarbon group; Z is --O--, --S--, --NR.sub.2--, --CONR.sub.2-- or --NR.sub.2CO-- (R.sub.2 is a hydrogen atom or an optionally substituted alkyl group); Y is a bond or a divalent acyclic hydrocarbon group; R.sub.1 is an optionally substituted cyclic group, an optionally substituted amino group or an optionally substituted acyl group, provided that when the 5-membered aromatic heterocycle represented by ring A is imidazole, then Z should not be --O--, or a salt thereof.