Levofloxacin is an optically active form of ofloxacin having (S)-configuration; an inhibitor of bacterial topoisomerase IV and DNA gyrase. It has a role as an antibacterial drug, an EC 5.99.1.3 [DNA topoisomerase (ATP-hydrolysing)] inhibitor, a topoisomerase IV inhibitor and a DNA synthesis inhibitor. It is a 9-fluoro-3-methyl-10-(4-methylpiperazin-1-yl)-7-oxo-2,3-dihydro-7H-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxylic acid, a quinolone antibiotic and a fluoroquinolone antibiotic. It is a conjugate acid of a levofloxacin(1-). It is an enantiomer of a dextrofloxacin.