The invention provides a pyrimidodiazepinone derivative represented by the general formula (I)
[wherein n represents 1 or 2, Z represents a hydrogen atom or the like, R1 and R2 may be the same or different, and each represents a hydrogen atom or the like, A represents a bond, (CH2)m (wherein m represents an integer of 1 to 4), optionally substituted phenylene, optionally substituted pyridinediyl, or C═O, R3 represents a hydrogen atom, optionally substituted lower alkyl, or the like, and R4 represents a hydrogen atom or the like], or a pharmaceutically acceptable salt thereof or the like.