SAN DIEGO, CA—Treatment with fluoroquinolones was definitely associated with subsequent tendon ruptures, and was found to be a possible contributor in aortic aneurysms, presented Nick Daneman, MD, MSc, from the University of Toronto, Ontario, Canada, at IDWeek 2015.

For fluoroquinolones, rare complications can pose significant health consequences because they are the most commonly used class of antibiotics. Tendon ruptures associated with fluoroquinolone use have been well demonstrated in literature but other more severe collagen-associated adverse events may be possible, explained Dr. Daneman. His team set out to: (1) confirm the link between fluoroquinolones and tendon rupture, (2) clarify the potential association of fluoroquinolones and retinal detachment, and (3) to test for a possibly lethal link between fluoroquinolone use and aortic aneurysms.

The longitudinal cohort study included older adults turning age 65 between April 1, 1997 and March 31, 2012 in Ontario, Canada (n=1,744,360). Patients were considered to be at risk during and for 30 days following treatment using fluoroquinolone use measured as a time-varying covariate. Tendon ruptures, retinal detachments, and aortic aneurysms diagnosed in province-wide hospital and emergency room datasets in Ontario’s universal healthcare system was used. Patients were followed until they experienced an outcome event, died, or reached the end of the follow-up period of March 31, 2014.

Of the total eligible older adults, 38% (n=657,950) had at least 1 fluoroquinolone during follow-up, totaling 22,380,515 days of fluoroquinolone treatment. Patients experienced a total of 2.1% (n=37,338) tendon ruptures, 1.1% (n=18,391) aortic aneurysms, and 0.2% (n=3,246) retinal detachments. Severe collagen-associated adverse events were more commonly seen during fluoroquinolone periods vs. aortic aneurysms, including tendon ruptures (0.82 vs. 0.26 per 100 person years; P<0.001), retinal detachments (0.03 vs. 0.02 per 100 person years; P=0.003), and aortic aneurysms (0.35 vs. 0.13 per 100 person years; P<0.001).

Further, fluoroquinolones were linked with increases in tendon rupture (hazard ratio [HR] 3.13, 95% CI: 2.98–3.28), and a comparable increase in aortic aneurysms (HR 2.72, 95% CI: 2.53–2.93). The risk of both adverse events was “substantially greater in magnitude than the association of these outcomes with amoxicillin,” noted Dr. Daneman. For the retinal detachment outcome, the hazard was marginal and not greater than that seen with amoxicillin (HR 1.28, 95% CI: 0.99–1.65).