ABSTRACT Background/Aims Determining antibiotic use history accurately is challenging due to its reliance on patient recall. By determining macrolide exposure using the Korean drug utilization review (DUR) system, we analyzed the impact of previous macrolide use on antibiotic resistance profiles and compared the eradication rate between tailored therapy based on macrolide exposure history and empirical therapy. Methods Patients with confirmed Helicobacter pylori ( H. pylori ) infection who agreed to access prescription information using the Health Insurance Review and Assessment Service DUR system were enrolled between 2021 and 2023. Patients received tailored therapy, which was clarithromycin (CLR)‐based triple therapy in cases without macrolide exposure and bismuth quadruple (BQ) therapy in cases with macrolide exposure. The empirical therapy group was prospectively recruited at the same time to compare the eradication rate. Results A total of 418 patients (tailored therapy group, n = 57; empirical therapy group, n = 361) were analyzed. Among the tailored therapy group, 24.6% took macrolide antibiotics for the past 5 years. CLR resistance rates were higher in patients with previous macrolide use than in those without (66.7% vs. 7.5%, p &lt; 0.001). The tailored therapy group showed a higher eradication rate than the empirical therapy group for intention‐to‐treat (ITT), modified intention‐to‐treat (MITT), and per‐protocol (PP) analyses (ITT, 86.0% vs. 75.6%; MITT, 94.2% vs. 80.3%; PP, 94.2% vs. 85.1%). Conclusions Previous macrolide exposure identified using the DUR system was associated with a higher rate of CLR resistance. Tailored therapy based on macrolide exposure history led to higher eradication rates compared to empirical therapy.

Effect of Macrolide Exposure on Tailored <i>Helicobacter pylori</i> Eradication Therapy and Antibiotic Resistance Profiles: A Prospective Study Using the Drug Utilization Review System

Effect of Macrolide Exposure on Tailored Helicobacter pylori Eradication Therapy and Antibiotic Resistance Profiles: A Prospective Study Using the Drug Utilization Review System