Norfloxacin 400mg is a fluoroquinolone antibiotic used to treat a variety of bacterial infections in different parts of the body, including the urinary tract, prostate, and gonorrhea. It works by blocking the DNA gyrase enzyme, which is responsible for the production and repair of bacterial DNA, leading to bacterial death and preventing the worsening of the infection. Norfloxacin treats infections caused by gram-positive and gram-negative bacteria, including Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Neisseria gonorrhoeae, Proteus mirabilis, Pseudomonas aeruginosa, and Serratia marcescens. It is important to note that Norfloxacin treats only bacterial infections and will not work for viral infections such as the common cold or flu. It is also important to use this medication for the full prescribed length of time, as skipping doses may increase the risk of further infection that is resistant to antibiotics.