Effective Eradication Regimen and Duration According to the Clarithromycin Susceptibility of Determined Using Dual Priming Oligonucleotide-Based Multiplex Polymerase Chain Reaction.

Background/aims: Dual priming oligonucleotide-based multiplex polymerase chain reaction (DPO-PCR) has recently been used for both the detection of and the identification of 23S ribosomal RNA point mutations that cause clarithromycin resistance. The aim of this study was to investigate the duration of effective standard triple therapy in a clarithromycin susceptible group and of bismuth-based quadruple therapy in a resistant group based on DPO-PCR.

Methods: We retrospectively analyzed the electronic medical records of 184 patients who, between September 2019 and December 2020, received eradication therapy following detection of , and the subsequent identification of the clarithromycin susceptibility of their using DPO-PCR. Patients were treated with 7- or 14-day standard triple therapy in the clarithromycin susceptible group, whereas 7- or 14-day bismuth-based quadruple therapy in the clarithromycin resistance group.

Results: In the clarithromycin susceptible group, per-protocol analyses showed eradication rates of 87.5% (42/48; 95% confidence interval [CI], 77.1% to 95.8%) for 7-day therapy and 87.2% (41/47; 95% CI, 78.7% to 95.7%) for 14-day therapy (p=0.969). The eradication rates in the clarithromycin resistance group were 91.4% (32/35; 95% CI, 80.0% to 100.0%) for 7-day therapy and 90.3% (28/31; 95% CI, 77.4% to 100.0%) for 14-day therapy (p=0.876). There was no significant difference in the eradication rates, patient compliance, or rate of adverse events between the 7- and 14-day therapies for both groups.

Conclusions: Compared to the 14-day therapy, 7-day eradication therapy is sufficient after DPO-PCR-based clarithromycin susceptibility testing.