CYP2C19 genotypes and Helicobacter pylori eradication

摘要

In the Maastricht-2 and -3 Consensus reports, two first-line proton pump inhibitor (PPI)-based triple therapy regimens were recommended. They are amoxicillin, clarithromycin, and PPI or metronidazole,clarithromycin, and PPI. In Asia, where metronidazole resistance is high, the regimen frequently selected is amoxicillin, clarithromycin, and PPI. With good compliance, the eradication outcome for Helicobacter pylori by this recommended first-line therapy is mainly determined by antimicrobial resistance to clarithromycin. A report in 2005 suggested that host factor, namely extensive metabolizers (EM) of CYP2C19, could result in a reduced eradication rate with triple therapy that combines clarithromycin, amoxicillin, and omeprazole, 20 mg twice daily. In an article in this issue of the Journal of Gastroenterology and Hepatology, a Korean group has confirmed that extensive metabolizers of CYP2C19 have a worse H. pylori eradication rate compared with poor metabolizers (PM) in a 7-day regimen using the same antibiotics combined with either esomeprazole 20 mg twice daily or pantoprazole 40 mg twice daily. In this head-to-head comparison, the H. pylori eradication rates were approximately 15% lower in the EM group than in the PM group. This is a significant finding for Asians, as PM account for 15-23% or more of the population.