Proton Pump Inhibitor Use and Risk of Serious Infections in Young Children

Importance Proton pump inhibitor (PPI) use may lead to infections through alteration of the microbiota or direct action on the immune system. However, only a few studies were conducted in children, with conflicting results. Objective To assess the associations between PPI use and serious infections in children, overall and by infection site and pathogen. Design, Setting, and Participants This nationwide cohort study was based on the Mother-Child EPI-MERES Register built from the French Health Data System (SNDS). We included all children born between January 1, 2010, and December 31, 2018, who received a treatment for gastroesophageal reflux disease or other gastric acid–related disorders, namely PPIs, histamine 2 receptor antagonists, or antacids/alginate. The index date was defined as the first date any of these medications was dispensed. Children were followed up until admission to the hospital for serious infection, loss of follow-up, death, or December 31, 2019. Exposure PPI exposure over time. Main Outcomes and Measures Associations between serious infections and PPI use were estimated by adjusted hazard ratios (aHRs) and 95% CIs using Cox models. PPI use was introduced as time-varying. A 30-day lag was applied to minimize reverse causality. Models were adjusted for sociodemographic data, pregnancy characteristics, child comorbidities, and health care utilization. Results The study population comprised 1 262 424 children (median [IQR] follow-up, 3.8 [1.8-6.2] years), including 606 645 who received PPI (323 852 male [53.4%]; median [IQR] age at index date, 88 [44-282] days) and 655 779 who did not receive PPI (342 454 male [52.2%]; median [IQR] age, 82 [44-172] days). PPI exposure was associated with an increased risk of serious infections overall (aHR, 1.34; 95% CI, 1.32-1.36). Increased risks were also observed for infections in the digestive tract (aHR, 1.52; 95% CI, 1.48-1.55); ear, nose, and throat sphere (aHR, 1.47; 95% CI, 1.41-1.52); lower respiratory tract (aHR, 1.22; 95% CI, 1.19-1.25); kidneys or urinary tract (aHR, 1.20; 95% CI, 1.15-1.25); and nervous system (aHR, 1.31; 95% CI, 1.11-1.54) and for both bacterial (aHR, 1.56; 95% CI, 1.50-1.63) and viral infections (aHR, 1.30; 95% CI, 1.28-1.33). Conclusions and Relevance In this study, PPI use was associated with increased risks of serious infections in young children. Proton pump inhibitors should not be used without a clear indication in this population.