The present invention provides a hetrodiazinon compound having 2-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor antagonistic action, which is represented by the following formula (I), a pharmacologically acceptable salt thereof or hydrates thereof. Wherein A represents O, S or a group represented by the formula NR3 (wherein R3 represents hydrogen atom or a lower alkyl group); R1 and R2 are the same as or different from each other and each represents an optionally substituted (hetero)aryl group etc.; and R4 and R5 are the same as or different from each other and each represents hydrogen atom, hydroxy, a halogen atom, nitrile group, nitro group, a lower alkyl group, a (hetero)aryl group etc.