Bactericidal and cytotoxic effect of combination of norfloxacin and 5-fluorouracil.

Using the agar dilution technique, we examined the in vitro antibacterial activity of 5-fluorouracil and norfloxacin alone and in association against several bacterial strains. When administered in association, the two drugs did not antagonize each other in tests carried out on strains both sensitive and resistant to penicillins, cephalosporins, aminoglycosides, tetracyclines; furthermore their respective antibacterial properties remained largely unimpaired. The cytotoxic activity and the antitumoral effect of a combination of 5-fluorouracil and norfloxacin was determined in cultured tumor cells, and in mice bearing Ehrlich ascites carcinoma. No significant interference with the cytotoxic activity and antitumoral activity of 5-fluorouracil was observed.