Findings demonstrated an elevated risk of serious hypoglycemia among fluoroquinolone users vs comparator antibiotic users. This link was observed only among individuals diagnosed with diabetes.

• This propensity score-matched cohort study, using Optum claims data, included 119,112 people with diabetes and 917,867 without diabetes exposed to fluoroquinolone, matched 1:1 with a comparator.

• The odds ratios for the link between fluoroquinolones and serious hypoglycemia was estimated to be 1.28, 1.30 and 1.06 in the whole cohort, in participants with diabetes, and in those without diabetes, respectively.