Fluoroquinolones (FQs) are one of the most prescribed classes of antibiotics and are favored
over other agents for their broad spectrum of
antibacterial activity and high oral absorption. In
recent years, a number of adverse events have been
linked to these drugs. Some of these adverse events
include retinal detachment, which has produced
mixed results , but others, including aortic aneurysm and dissection , peripheral neuropathy , and cardiac arrhythmias , are more consistent with a causal link with FQs and are now included
in a warning from the U.S. Food and Drug Administration (FDA)
Mechanistically, FQs are known to damage connective tissue by inducing oxidative stress within the
tendon cells , reducing collagen production , and stimulating the activity of metalloproteinases , all of which may lead to reduction in the integrity of the extracellular matrix .
FQs can damage type I and III collagen that is
present in the Achilles tendons , aorta , and
aortic valves . The putative chain of pathophysiological events would include FQs that, through their
high bioavailability and chelating properties, bind to
the collagen leading to eventual degradation of the
collagen matrix of the aortic or possibly the mitral
valve. This can lead to subsequent aortic or mitral
valve regurgitation. This hypothesis has been
observed in at least 1 case report where a patient who
took ciprofloxacin (750 mg twice daily) for 2 days
developed symptoms of decompensation as a result
of aortic valve prolapse that, following a cardiac
work-up, could only be linked to ciprofloxacin use . The acute onset of collagen damage with FQs has
also been shown to lead to rupture of large tendons
within hours and aortic dissection within
days .
