Fluoroquinolone antibiotics may double the risk of regurgitation in valves on the left side of the heart, a study shows.

The finding comes from an analysis of data on more than nine million patients from a US medical claims database that researchers used to compare 12,500 people who developed aortic or mitral valve disease with more than 125,000 who did not.

Of those who developed valve disease, 2.4% were regarded as ‘currently taking oral fluoroquinolones’ (meaning, they were either taking them or had used them within the past 30 days).

However, just 0.53% of the controls were currently taking fluoroquinolones, the authors reported in the Journal of the American College of Cardiology.