title: Comparative effect of tetracycline and doxycycline on the occurrence of resistant Escherichia coli in the fecal flora.
abstract: Antibiotic-induced changes in the fecal microflora after oral administration of tetracycline hydrochloride and doxycycline for 8 to 10 days were compared. A significant difference was noted in the concentrations of Escherichia coli resistant to tetracyclines. With tetracycline hydrochloride, there was a mean increase of approximately 10(4) resistant strains per g compared to only 10(1)/g for doxycycline. This difference is ascribed to reduced intestinal concentrations of bioactive drug with recommended oral dosage for doxycycline.
mesh_terms: D004318:Doxycycline / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects*; D005243:Feces / Q000382:microbiology*; D006801:Humans; D013752:Tetracycline / Q000494:pharmacology*
chemical_list: D013752:Tetracycline; D004318:Doxycycline