A pyrazine derivative represented by the following formula or a pharmaceutically acceptable salt thereof, or a solvate thereof: wherein, X 1 represents a nitrogen atom or CH; R 1 represents a hydrogen atom, a C 1 -C 6 alkyl group, a C 3 -C 6 cycloalkyl group, a C 2 -C 6 alkenyl group, a C 2 -C 6 alkynyl group, a halogen atom, a trifluoromethyl group, a difluoromethyl group, a cyano group, a C 2 -C 7 alkylcarbonyl group, a C 1 -C 6 alkylsulfonyl group, a nitro group, an amino group, a di(C 1 -C 6 alkyl)amino group, a formyl group, a hydroxyl group, a C 1 -C 6 alkoxy group, a C 1 -C 6 alkylthio group, or a phenyl group or phenoxy group which may be substituted with 1 to 3 R a 's; R a represents a halogen atom, a C 1 -C 6 alkyl group, a C 3 -C 6 cycloalkyl group, or a C 1 -C 6 alkoxy group; R 2 represents a C 1 -C 6 alkyl group, a C 3 -C 6 cycloalkyl group, or a C 1 -C 6 alkoxy group; p represents any integer of 0 to 2; R 3 represents a hydrogen atom, a C 1 -C 6 alkyl group, a C 3 -C 6 cycloalkyl group, a C 2 -C 6 alkenyl group, a C 2 -C 6 alkynyl group, a C 1 -C 6 alkoxy group, a C 2 -C 7 alkylcarbonyl group, a C 1 -C 6 alkylthio group, a halogen atom, a trifluoromethyl group, a difluoromethyl group, a cyano group, a phenyl group, a pyridyl group, a phenoxy group, or a COOR b; R 4 represents a tetrazolyl group, -COOR c, -CONHSO 2 -(C 1 -C 6 alkyl), or any one of the following groups: R b and R c may be the same or different and represent a hydrogen atom, or a C 1 -C 6 alkyl group; Z represents any one of the following groups represented by Z1 to Z7: R 5 represents a hydrogen atom or a C 1 -C 6 alkyl group; R 6 and R 7 may be the same or different and represent a hydrogen atom, a halogen atom, a C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy group, a trifluoromethyl group, a trifluoromethoxy group, a cyano group, a nitro group, or a phenoxy group, or R 6 and R 7 together form a C 1 - C 3 alkylenedioxy group; R 8, R 9, R 10, R 11, R 12, R 13, R 14, and R 15 each independently represent a hydrogen atom, a halogen atom, a C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy group, a difluoromethyl group, a trifluoromethyl group, a cyano group, or a di (C 1 -C 6 alkyl)amino group; R 16 and R 17 may be the same or different and represent a halogen atom; q and r independently represent 0 or 1; W represents a sulfur atom, an oxygen atom, or NR d; and R d represents a hydrogen atom, a C 1 -C 6 alkyl group, or a benzyl group. X 1 represents a nitrogen atom or CH; R 1 represents a hydrogen atom, a C 1 -C 6 alkyl group, a C 3 -C 6 cycloalkyl group, a C 2 -C 6 alkenyl group, a C 2 -C 6 alkynyl group, a halogen atom, a trifluoromethyl group, a difluoromethyl group, a cyano group, a C 2 -C 7 alkylcarbonyl group, a C 1 -C 6 alkylsulfonyl group, a nitro group, an amino group, a di(C 1 -C 6 alkyl)amino group, a formyl group, a hydroxyl group, a C 1 -C 6 alkoxy group, a C 1 -C 6 alkylthio group, or a phenyl group or phenoxy group which may be substituted with 1 to 3 R a 's; R a represents a halogen atom, a C 1 -C 6 alkyl group, a C 3 -C 6 cycloalkyl group, or a C 1 -C 6 alkoxy group; R 2 represents a C 1 -C 6 alkyl group, a C 3 -C 6 cycloalkyl group, or a C 1 -C 6 alkoxy group; p represents any integer of 0 to 2; R 3 represents a hydrogen atom, a C 1 -C 6 alkyl group, a C 3 -C 6 cycloalkyl group, a C 2 -C 6 alkenyl group, a C 2 -C 6 alkynyl group, a C 1 -C 6 alkoxy group, a C 2 -C 7 alkylcarbonyl group, a C 1 -C 6 alkylthio group, a halogen atom, a trifluoromethyl group, a difluoromethyl group, a cyano group, a phenyl group, a pyridyl group, a phenoxy group, or a COOR b; R 4 represents a tetrazolyl group, -COOR c, -CONHSO 2 -(C 1 -C 6 alkyl), or any one of the following groups: R b and R c may be the same or different and represent a hydrogen atom, or a C 1 -C 6 alkyl group; Z represents any one of the following groups represented by Z1 to Z7: R 5 represents a hydrogen atom or a C 1 -C 6 alkyl group; R 6 and R 7 may be the same or different and represent a hydrogen atom, a halogen atom, a C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy group, a trifluoromethyl group, a trifluoromethoxy group, a cyano group, a nitro group, or a phenoxy group, or R 6 and R 7 together form a C 1 - C 3 alkylenedioxy group; R 8, R 9, R 10, R 11, R 12, R 13, R 14, and R 15 each independently represent a hydrogen atom, a halogen atom, a C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy group, a difluoromethyl group, a trifluoromethyl group, a cyano group, or a di (C 1 -C 6 alkyl)amino group; R 16 and R 17 may be the same or different and represent a halogen atom; q and r independently represent 0 or 1; W represents a sulfur atom, an oxygen atom, or NR d; and R d represents a hydrogen atom, a C 1 -C 6 alkyl group, or a benzyl group.