DiscussionThis large, multicenter, retrospective cohort study compared 3747 patients receiving lansoprazole during ceftriaxone therapy vs 27 405 patients receiving other PPIs during ceftriaxone therapy. The lansoprazole group had higher risk of ventricular arrhythmia or cardiac arrest with an adjusted risk difference of 1.7% (95% CI, 1.1%-2.3%). This corresponded to a number needed to harm of 58.8. In addition, the lansoprazole group had a higher risk of all-cause in-hospital mortality with an adjusted risk difference of 7.4% (95% CI, 6.1%-8.8%).