Antimicrobial activity of norfloxacin in enteric and urinary tract infections: combined effect of norfloxacin with aminoglycosides, tetracycline and chloramphenicol.

A comparative study of the in vitro activity of norfloxacin was performed versus that of aminoglycosides, pipemidic acid, tetracycline and chloramphenicol. These antibiotics are the most commonly used antimicrobial agents in the treatment of enteric and urinary tract infections. Results obtained with norfloxacin against Gram-negative isolates tested were very encouraging. MIC values for the Enterobacteriaceae were less than or equal to 0.47 mcg/ml, and for Pseudomonas and Acinetobacter less than or equal to 32.5 mcg/ml. The activity of norfloxacin against Pseudomonas was inferior to that of amikacin, but superior to that of gentamicin. In association with aminoglycosides, norfloxacin proved to be most useful in the treatment of urinary tract infections, while norfloxacin associated with tetracycline and chloramphenicol did not give satisfactory results in the treatment of enteric infections.