title: Potentiation of the action of metronidazole on Helicobacter pylori by omeprazole and bismuth subcitrate.
abstract: Treatment failures using triple therapy that include metronidazole, are common in patients infected with metronidazole-resistant Helicobacter pylori in the gastric mucosa. Higher eradication rates in such patients have been described when treatment regimens include bismuth salts compared to regimens that include proton pump inhibitors. In the present study, the synergistic effect of subinhibitory concentrations (0.25-0.5 MIC) of either bismuth subcitrate or omeprazole with metronidazole on the susceptibility of 42 H. pylori strains was investigated by agar dilution method and the Epsilometer test (Etest). With 0.5 MIC of either of the two drugs, the susceptibility of all H. pylori4 mg/l) reverted to being metronidazole sensitive. These results suggested that either bismuth salts or proton pump inhibitors may be effective in the treatment of some infections with metronidazole-resistant H. pylori strains when used in sufficiently high doses.
authors.affiliation: Department of Clinical Microbiology 7806, National University hospital (Rigshospitalet), Tagensvej 20, DK-2200, Copenhagen, Denmark. lpa@biobase.dk
authors.forename: L P
authors.initials: LP
authors.lastname: Andersen
authors.forename: H
authors.initials: H
authors.lastname: Colding
authors.forename: J E
authors.initials: JE
authors.lastname: Kristiansen
mesh_terms: D000863:Antacids / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004357:Drug Synergism; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D008795:Metronidazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D009853:Omeprazole / Q000494:pharmacology*; D009942:Organometallic Compounds / Q000494:pharmacology*
chemical_list: D000863:Antacids; D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D009942:Organometallic Compounds; D008795:Metronidazole; C002791:bismuth tripotassium dicitrate; D009853:Omeprazole