Norfloxacin is a third-generation quinolone antimicrobial drug that inhibits bacteria and blocks bacterial DNA replication and pathogenic bacterial DNA rotamases. Dosage varies depending on the disease. Simple gonococcal urethritis (800-1200mg once), intestinal infections (300-400mg once, twice a day for 5-7 days), acute and chronic prostatitis (400mg once, twice a day for 28 days), Salmonella infections (800-1200mg twice or thrice a day for 14-21 days). Acute simple lower urinary tract infections caused by Klebsiella pneumoniae, Escherichia coli and Aspergillus chimaera 400mg once, twice a day for 3 days; other pathogenic bacteria caused by the same dose, to 7-10 days; complex urinary tract infections the same dose, 10-21 days. Adverse reactions include gastrointestinal, central nervous system, and allergic reactions, and occasionally seizures and knee pain. This drug is contraindicated in minors because it delays bone formation and interferes with development. It is also contraindicated in people who are allergic to this drug. The exact dosage should also be advised by a medical professional and should not be taken blindly.