Rationale for the choice of antibiotics for the eradication of Helicobacter pylori.

AIM: To review data on the efficacy of antibiotics currently available for the eradication of Helicobacter pylori.
RESULTS: The main problem with current therapy is the resistance of H. pylori to the compounds used, with the exception of amoxycillin and tetracyclines. Primary resistance to metronidazole reaches 80-90% in tropical countries and may reach 50% in some European countries. Primary resistance to macrolides does occur but at a much lower level, although apparently linked to the level of consumption of these drugs in a given country. Resistance may also be acquired during monotherapy with antibiotics. Most of the antimicrobial agents, except bismuth salts, have a systemic effect. Nevertheless, their activity is dependent on the pH of the stomach because H. pylori lives in the mucus. Compounds that may achieve high mucosal concentrations, such as macrolides, are effective when the stomach pH is raised. The growth of H. pylori as sessile organisms may impair antibiotic efficacy.
CONCLUSIONS: The best eradication rate is achieved when two antimicrobial agents are used in combination with an antisecretory compound. Amoxycillin+clarithromycin with a proton-pump inhibitor is therefore recommended.