Investigations into the mechanism of action of the antibacterial agent norfloxacin.

Examination of the mechanism of action of norfloxacin upon susceptible strains of Escherichia coli K12 has shown that the drug exerts a potent bactericidal effect resulting from the inhibition of the A subunit of the essential enzyme DNA gyrase. It is also shown that the use of norfloxacin can reduce the total number of bacteria at the site of an infection as well as having significant effects upon the metabolism of treated cells in the interim period between the loss of viability and cell-lysis. These effects may provide a clue to a previously unsuspected mechanism of providing symptomatic relief which functions in parallel with the elimination of viable pathogenic bacteria.