[Helicobacter pylori erradication and its relation to antibiotic resistance and CYP2C19 status]. / Erradicación de H. pylori y su relación con la resistencia a los antibióticos y el estatus de CYP2C19.

ABSTRACT

OBJECTIVE: to assess the efficacy of rabeprazole (RPZ), amoxicillin (Am), and clarithromycin (Cla) (7 vs. 14 days) in the eradication of H. pylori, and to determine the effect of strain-specific antibiotic resistance and host CYP2C19 status. MATERIAL AND METHODS: first, we determined the CYP2C19 status of 100 healthy subjects to establish a sample size for the clinical trial. Then, 59 H. pylori-infected patients were randomized to receive RPZ (20 mg daily) plus Cla (500 mg b.d.) and Am (1,000 mg b.d.) for 7 vs. 14 days. The MIC for Am and Cla were determined using the agar dilution method. The CYP2C19 genotype was determined by the PCR-RFLP method. RESULTS: In the per-protocol analysis (PP) eradication rates were 89.7 and 72% for the 7- and 14-day groups (p = 0.159). In the intention to-treat analysis (ITT) eradication rates were 86.7 and 62.1% in the 7- and 14-day groups, respectively (p = 0.06). None of the strains was resistant to Am, and 4 strains were resistant to Cla 3 (11.1%) in the 14-day group and 1 (4%) in the 7-day group. Neither strain-specific antibiotic resistance nor host CYP2C19 status influenced eradication rates. CONCLUSIONS: both 7- and 14-day therapies were effective for H. pylori eradication. Strain resistance and CYP2C19 status do not seem to influence eradication rates in the studied population.