title: Synergic interactions of macrolides and proton-pump inhibitors against Helicobacter pylori: a comparative in-vitro study.
abstract: Thirty-eight clinical strains of Helicobacter pylori were isolated from patients with chronic gastritis and gastroduodenal ulceration, and their susceptibility to macrolide antibiotics (roxithromycin, flurithromycin, azithromycin, erythromycin) in combination with proton-pump inhibitors (lansoprazole and omeprazole) and bismuth subcitrate was assayed. Chequerboard titration was used to analyse the results of antimicrobial interactions and showed that the activity of macrolides was enhanced by combining them with lansoprazole, omeprazole or, to a lesser extent, bismuth subcitrate. While the interactions between erythromycin and the proton-pump inhibitors or bismuth subcitrate were always additive, the combinations of roxithromycin-lansoprazole, flurithromycin-omeprazole and azithromycin-lansoprazole acted synergically on 82%, 60% and 60% of H. pylori strains, respectively. These results may, in part, account for the enhanced clinical efficacy of macrolides administered with proton-pump inhibitors in the treatment of H. pylori-associated diseases.
authors.affiliation: Dipartimento di Biomedicina Sperimentale, Infettiva e Pubblica, Università degli Studi di Pisa, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Malizia
authors.forename: M
authors.initials: M
authors.lastname: Tejada
authors.forename: F
authors.initials: F
authors.lastname: Marchetti
authors.forename: P
authors.initials: P
authors.lastname: Favini
authors.forename: G
authors.initials: G
authors.lastname: Pizzarelli
authors.forename: M
authors.initials: M
authors.lastname: Campa
authors.forename: S
authors.initials: S
authors.lastname: Senesi
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology*; D004357:Drug Synergism; D004917:Erythromycin / Q000031:analogs & derivatives / Q000494:pharmacology*; D005753:Gastric Mucosa / Q000382:microbiology; D005756:Gastritis / Q000382:microbiology; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D064747:Lansoprazole; D008826:Microbial Sensitivity Tests; D009853:Omeprazole / Q000031:analogs & derivatives / Q000494:pharmacology; D009942:Organometallic Compounds / Q000494:pharmacology; D010437:Peptic Ulcer / Q000378:metabolism; D054328:Proton Pump Inhibitors; D015575:Roxithromycin / Q000494:pharmacology*
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D009942:Organometallic Compounds; D054328:Proton Pump Inhibitors; D064747:Lansoprazole; D015575:Roxithromycin; C045925:flurithromycin; D004917:Erythromycin; D017963:Azithromycin; C002791:bismuth tripotassium dicitrate; D009853:Omeprazole