What can be learnt from the new data about antibiotic resistance? Are there any practical clinical consequences of Helicobacter pylori antibiotic resistance?
Effective treatment regimens are now available for the eradication of Helicobacter pylori, but one of the factors limiting their efficacy is antibiotic resistance. Omeprazole-based triple therapy (omeprazole plus two antibiotics) can, at present, be considered the treatment of choice for H. pylori infection; some of the best results have been achieved by combining omeprazole with either amoxycillin and clarithromycin or metronidazole and clarithromycin. However, the potential effectiveness of nitroimidazole derivatives and clarithromycin must be weighed against the possibility that resistance can develop to these agents. Eradication in metronidazole-resistant strains is lower than in sensitive strains, but is still about 75% (versus 97%). However, clarithromycin resistance is thought to have more clinical significance, reducing the eradication rate of 95% in sensitive strains to 40% in resistant strains, although the overall importance of clarithromycin resistance for H. pylori eradication is still likely to be relatively low. Recent data on secondary resistance indicate that the rate is at least 50% for both metronidazole and clarithromycin in patients in whom eradication has failed. If, in the future, a large number of H. pylori-positive individuals undergo such treatment, treatment failures may become a major issue, and the problem of antibiotic resistance will have to be overcome.
Bazzoli
F
F
Department of Gastroenterology, University of Bologna, Italy. bazzoli@alma.unibo.it
Berretti
D
D
De Luca
L
L
Nicolini
G
G
Pozzato
P
P
Fossi
S
S
Zagari
M
M
D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D017291:Clarithromycin / Q000627:therapeutic use; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D008795:Metronidazole / Q000494:pharmacology / Q000627:therapeutic use*; D009853:Omeprazole / Q000627:therapeutic use; D013752:Tetracycline / Q000627:therapeutic use; D013753:Tetracycline Resistance; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D004791:Enzyme Inhibitors; D008795:Metronidazole; D013752:Tetracycline; D017291:Clarithromycin; D009853:Omeprazole