The present invention provides an antidiabetic therapeutic agent which can be decreased in dosage and is capable of excellently controlling the blood sugar level of a diabetic patient, while suppressing side effects. Provided is an insulin secretagogue which contains, as active ingredients: a compound represented by general formula (I) (wherein R1 represents a hydrogen atom, a halogen, a nitro, a cyano, a C1-6 alkyl, a C3-6 cycloalkyl, a C2-6 alkenyl, a C2-6 alkynyl, -OR3, -CH2OR4, -COOR5, -COR6 or -CON(R7)R8; and R2 represents a hydrogen atom, a halogen, a nitro, a cyano, -OR9, an optionally substituted C1-6 alkyl, C3-6 cycloalkyl, C2-6 alkenyl or C2-6 alkynyl), or a pharmaceutically acceptable salt or solvate of the compound; and a sugar nucleotide or glucosamine.