Pneumonia is an infection that occurs in one or both lungs and is characterized by the inflammation of alveoli. Proton pump inhibitors (PPIs) have become increasingly popular in the treatment of various medical conditions, like acid-related gastrointestinal disorders. This study aims to investigate the risk of community-acquired pneumonia before and after the prescription of PPI.

This cohort study and self-controlled case series included a total of 160,000 participants with a new prescription for a PPI. The participants were matched with controls. The primary outcome of the study was the risk of community-acquired pneumonia determined using the following models: a multivariable Cox model, a self-controlled case series, and a prior event rate ratio (PERR) analysis.

The adjusted Cox regression indicated that the risk of community-acquired pneumonia was 1.67 times higher among patients exposed to PPIs, as compared with controls. The results of the self-controlled case series suggested that the incidence ratio of community-acquired pneumonia for patients exposed to PPIs was 1.92 in the first 30 days after treatment initiation and 1.19 after 30 days. The Cox regression for PERR also indicated a higher risk of community-acquired pneumonia in the first-year after PPI prescription.

The research concluded that the use of PPIs was associated with an increased risk of community-acquired pneumonia.