A compound represented by general formula (II) (in the formula Rand Rcan be the same or different and can represent hydrogen atoms or Calkyl groups R represents a hydrogen atom or a C alkyl group R represents a hydrogen atom a C alkyl group a C alkoxy group a C alkyl group which has 1 3 halogen substituents a C alkyl group which has a hydroxyl group substituent a halogen atom a hydroxyl group a nitro group a cyano group an amino group a C alkylamino group an optionally substituted benzenesulfonyl amino group or an optionally substituted heterocyclic group etc. and chemical formula (7) represents a naphthalene ring a tetrahydronaphthalene ring or an indane ring) or a pharmacologically acceptable salt thereof is used as a P2X receptor antagonist.
