Alkoxycarbonyl hemiacetal-type ester prodrug of pyridone carboxylic acid antibacterial drug

Provided is a pyridone carboxylic acid antibacterial drug prodrug with which hydrolysis occurs quickly after gastrointestinal absorption so that the pyridone carboxylic acid antibacterial drug that is the active ingredient is regenerated; a one-dose preparation is possible according to the inhibiting effect on intestinal chelation with oral administration; and, because the carboxylic acid that is the center of antibacterial activity is in the form of a hemiacetal-type ester, the normal intestinal flora are left completely unaffected until the drug is absorbed so that pseudomembranous colitis is unlikely to occur. The prodrug is an alkoxycarbonyl hemiacetal-type ester of a pyridone carboxylic acid antibacterial drug that is represented by a chemical formula (1) and that can be used to inhibit the adverse effects of intestinal bacterial replacement and/or can be used in combination with polyvalent metal-containing drugs.