title: Drug combinations with amoxycillin reduce selection of clarithromycin resistance during Helicobacter pylori eradication therapy.
abstract: This study investigated the relationship between the drug combinations of the eradication regimens and the prevalence of acquired resistance to clarithromycin. Of 540 patients treated with anti-Helicobacter pylori regimens containing clarithromycin, 55 patients (31 males, mean age, 45.6 years) with failed eradication of H. pylori that was susceptible to clarithromycin before treatment were included. The E test was used to test for susceptibility to clarithromycin (minimum inhibitory concentration (MIC) <1 mg/l). Of the 55 patients, 33 (60.0%) developed clarithromycin resistance after failed eradication. Of the dual therapies, the combination of a proton pump inhibitor (PPI) and clarithromycin resulted in 88.9% (8/9) of the patients acquiring clarithromycic-resistance. With the triple therapies, the percentages of patients acquiring clarithromycin resistant strains after using a PPI+clarithromycin+amoxycillin or a PPI+clarithromycin+metronidazole were 38.7% (12/31) and 90.0% (9/10), respectively (P<0.01). These data suggest that regimens containing amoxycillin may prevent the selection of secondary clarithromycin resistance.
authors.affiliation: The Second Department of Internal Medicine, Oita Medical University, 1-1 Hasama, 879-5593, Oita, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Murakami
authors.forename: T
authors.initials: T
authors.lastname: Fujioka
authors.forename: T
authors.initials: T
authors.lastname: Okimoto
authors.forename: R
authors.initials: R
authors.lastname: Sato
authors.forename: M
authors.initials: M
authors.lastname: Kodama
authors.forename: M
authors.initials: M
authors.lastname: Nasu
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000658:Amoxicillin / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001562:Benzimidazoles / Q000627:therapeutic use; D017291:Clarithromycin / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D064747:Lansoprazole; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009853:Omeprazole / Q000031:analogs & derivatives* / Q000627:therapeutic use; D054328:Proton Pump Inhibitors; D064750:Rabeprazole; D012189:Retrospective Studies
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000900:Anti-Bacterial Agents; D001562:Benzimidazoles; D004791:Enzyme Inhibitors; D054328:Proton Pump Inhibitors; D064747:Lansoprazole; D008795:Metronidazole; D064750:Rabeprazole; D000658:Amoxicillin; D017291:Clarithromycin; D009853:Omeprazole