The present invention provides nitrogen-containing fused cyclic derivatives represented by the following general formula or pharmaceutically acceptable salts thereof, or prodrugs thereof, which exhibit an excellent inhibitory activity in human SGLT and are useful as agents for the prevention or treatment of a disease associated with hyperglycemia such as diabetes, postprandial hyperglycemia, impaired glucose tolerance, diabetic complications or obesity, in the formula one of R1 and R4 represents a group represented by the following general formula (S) (in which R5 and R6 represent H, OH, a halogen atom, etc. Q represents an alkylene group etc. and ring A represents an aryl group etc.), and the other represents H, OH, an amino group, etc. R2 and R3 represent H, OH, an amino group, a halogen atom, and an optionally substituted alkyl group, etc. A1 represents O, S, etc. A2 represents CH or N G represents a group represented by the following general formula (G-1) or (G-2) (E1 represents H, F or OH and E2 represents H, F, a methyl group, etc.), and pharmaceutical compositions comprising the same, and pharmaceutical uses thereof.
