Development status: Approved, off-patent, discontinued in most countries

Gram-negative activity

Mechanism of Action/Target pathogen: Binds to type II topoisomerases, gyrase and topoisomerase IV and thus, inhibits DNA cleavage and ligation reactions. It kills bacterial cells by increasing the concentration of enzyme–DNA cleavage complexes, thereby inhibiting cell replication.

Additional information: Synthetic pyridopyrimidine compound, derivative of piromidic acid. Similar to nalidixic acid. Also used as K+ channel blocker.