In vitro interactions between metronidazole or tinidazole and ampicillin, doxycycline and co-trimoxazole on the effect against anaerobic bacteria.
The mutual interaction on the antibacterial activity of metronidazole and tinidazole with ampicillin, doxycycline and co-trimoxazole was studied by two-fold agar dilution series and chess-board determinations with 24 anaerobic bacterial strains which were recent clinical isolates. The nitroimidazoles had similar activity, and partial or complete synergy was observed in 83 - 88% of the strains when they were combined with ampicillin and doxycycline and 83 - 100% when combined with co-trimoxazole, which was moderately less active on a weight basis. A combination between ampicillin and a nitroimidazole would be preferable due to high level of synergy, high activity against anaerobes, and a more consistent supplementary activity against enterococci.
D000667:Ampicillin / Q000494:pharmacology*; D001421:Bacteria, Anaerobic / Q000187:drug effects*; D004318:Doxycycline / Q000494:pharmacology*; D004336:Drug Antagonism; D004338:Drug Combinations / Q000494:pharmacology; D004357:Drug Synergism; D008795:Metronidazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D009593:Nitroimidazoles / Q000494:pharmacology*; D010403:Penicillin Resistance; D013420:Sulfamethoxazole / Q000494:pharmacology*; D014011:Tinidazole / Q000494:pharmacology*; D014295:Trimethoprim / Q000494:pharmacology*; D015662:Trimethoprim, Sulfamethoxazole Drug Combination
D004338:Drug Combinations; D009593:Nitroimidazoles; D014011:Tinidazole; D008795:Metronidazole; D000667:Ampicillin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D014295:Trimethoprim; D013420:Sulfamethoxazole; D004318:Doxycycline