Practical Efficacy of a 1-Week Metronidazole-Based Triple Regimen Plus Bismuth Versus a 2-Week Bismuth-Based Quadruple Regimen for Helicobacter pylori Infection With Clarithromycin-Resistance-Associated Genetic Mutations.

Objective: For patients with clarithromycin-resistant Helicobacter pylori infection, a 2-week bismuth quadruple therapy (2W-PBMT) is typically recommended. However, a recent Korean guideline suggests a 1-week metronidazole-based regimen (PMA) as an alternative. This study aimed to evaluate whether a 1-week PMA plus bismuth (1W-PBMA) could achieve comparable efficacy to the conventional 2W-PBMT.

Methods: This study retrospectively analyzed medical records from two academic hospitals and employed propensity score matching (PSM) to minimize confounding variables.

Results: A total of 121 patients with confirmed H. pylori infection and clarithromycin resistance-related genetic mutations were identified via polymerase chain reaction. After excluding six patients with the A2142G mutation, 115 patients with the A2143G mutation were enrolled. Among them, 82 patients who received an eradication regimen were included in the final analysis. Fifty-one patients received the conventional 2W-PBMT, while 31 received the 1W-PBMA regimen. PSM resulted in 25 matched cases in each group. Before PSM, eradication rates were 70.6% (2W-PBMT) vs. 77.4% (1W-PBMA) in the intention-to-treat (ITT) analysis and 94.7% vs. 85.7% in the per-protocol (PP) analysis, with no significant differences. After PSM, ITT eradication rates were 68.0% (2W-PBMT) vs. 80.0% (1W-PBMA), while PP eradication rates were 94.4% vs. 87.0%, again showing no statistical significance. Medication adherence exceeded 85% in both groups, with comparable incidences of adverse events. However, the 2W-PBMT group had a slightly higher discontinuation rate due to intolerable side effects.

Conclusions: In patients with H. pylori infection harboring the A2143G point mutation, the 1W-PBMA regimen demonstrated comparable eradication efficacy to the 2W-PBMT regimen, with potentially fewer intolerable adverse effects and improved adherence.