[Helicobacter pylori infection. Frequency of first-line treatment failure].

: Antibiotic resistance may hinder the efficacy of eradication therapy against Helicobacter pylori infection and it has become a major concern worldwide. Due to the relatively scarce evidence published in Argentina on this topic, our aim was to describe factors associated with H. pylori persistence after antibiotic treatment. The therapeutic failure rate was described among 81 patients with H. pylori gastritis treated in our Hospital with a post-treatment urea breath test to determine successful eradication. Mean age was 58 ± 12 and 43.2% were male subjects. H. pylori persistence was observed in 17.3% of subjects. Therapeutic failure was more common among patients receiving clarithromycin + amoxicillin therapy that among those receiving levofloxacin + amoxicillin (25% vs. 6.6%, p = 0.04). The following variables were assessed: age, gender, referral symptoms, smoking, anti-inflammatory use, diabetes, obesity, treatment type and duration. Clarithromycin-based therapy and male gender were associated with infection persistence on univariate analysis [OR 4.2 (1.1-15.6) and 5.2 (1.1-26.4)]. On multivariate analysis, clarithromycin-based was associated with infection persistence [5.38 (1.1-29.5)]. We conclude that clarithromycinbased therapy is significantly associated with treatment failure. This failure may be due to an elevated prevalence of H. pylori resistance to clarithromycin in the population under study and raises the question on the utility of such therapeutic alternative.