The influence of quinolones on the faecal flora.

Ingestion of antimicrobial agents may in several ways influence the indigenous flora of the human digestive tract. The influence can be evaluated by following qualitative and/or quantitative alterations in the composition of the flora and of its antibiotic resistance profile (ARP). Another approach is to follow alterations in physiological and/or biochemical intestinal characteristics which depend on the intestinal flora. In a Norwegian-Swedish collaborative study, the influence of 10 orally given antimicrobial drugs on seven to nine various biochemical microflora-associated characteristics in groups of healthy volunteers was followed. In contrast to most of the other drugs given, ofloxacin exerted almost no influence upon the characteristics investigated. The result of this study are reviewed, as well as the results of other studies dealing with the influence of the quinolones on the faecal flora.