Proton pump inhibitors and community acquired pneumonia

Concerns about proton pump inhibitors (PPIs) and the risk of community acquired pneumonia initially arose in 2004 after the publication of a nested case-control study,1 in which the risk of community acquired pneumonia was significantly higher among current users of PPIs than among those who had discontinued use. This finding was supported by a strong biological rationale: acid suppression may result in bacterial overgrowth and an increased risk of bacterial aspiration. Several observational studies and corresponding meta-analyses have subsequently been conducted.2 3 The most recent meta-analysis found that PPIs were associated with an increased risk of community acquired pneumonia (pooled estimate 1.49, 95% confidence interval 1.16 to 1.92; I²=99.2%).3 Although formal meta-analysis of these data is probably inappropriate given the presence of substantial heterogeneity, a qualitative review of the same data also suggests that PPI users are at an increased risk of community acquired pneumonia.

In The BMJ (doi:10.1136/bmj.i5813), Othman and colleagues report the …