The present invention provides a novel P2X 3 and/or P2X 2 / 3 receptor antago nist. A compound represented by the formula (I): wherein Z 1 is optionally protected hydroxy, etc.； Z 2 is -C(=O)-, etc.； Z 3a and Z 3b are taken together =O or =S； t is an integer of 0 to 4； R 4a and R 4b are each independently, hydrogen or substituted or unsubstituted lower alkyl, etc.； m and n are each independently an integer of 0 to 2； k is an integer of 0 or 1； Ring A is an aromatic carbocyclic ring or a heterocyclic ring, etc.； B is aromatic carbocyclic ring-diyl or heterocyclic ring-diyl, etc.； R 1a and R 1b are each independently halogen, hydroxy, substituted or unsubstituted lower alkyl, etc.； R 2 is substituted or unsubstituted alkyl, etc. R 3 is substituted or unsubstituted alkyl, substituted or unsubstituted aryl or a substituted or unsubstituted heterocyclic group, etc.； or its pharmaceutically acceptable salt, or a solvate thereof is provided.
