Hepatic and intestinal effects of flurithromycin and erythromycin in the rat

The effects of flurithromycin (30-100 mg/kg p.o.), a fluorinated macrolide, on rat hepatic enzymes and intestinal microflora have been compared with those of equal doses of erythromycin. This latter drug significantly decreases cytochrome b5, cytochrome P-450 and aminopyrine N-demethylase and moderately influences intestinal microbial flora. Flurithromycin showed almost opposite characteristics, with no hepatic interaction and marked effects on some bacterial species (e.g. Bacteroides) known to facilitate the colonization of pathogenetic bacteria.