Cell wall synthesis, protein synthesis, ribonucleic acid synthesis, deoxyribonucleic acid synthesis, and intermediary metabolism are the targets of antimicrobial drugs. It has been known that fluoroquinolones are the only direct inhibitors of DNA synthesis by binding to the enzyme-DNA complex which stabilizes DNA strand breaks created by DNA gyrase and Topoisomerase. Studies have shown that ternary complexes of the drug, enzyme, and DNA block the progress of replication fork. The action of fluoroquinolones involves the a) conversion of topoisomerase-quinolone-DNA complex to an irreversible form and b) generation of double-strand break by denaturation of topoisomerase.