Antibiotic Side Effects Linked to Aortic Aneurysm, Dissection Risk in Mice: Study

A new study warns that the side effects of antibiotics like Cipro, Levaquin and Avelox may increase the risk of aortic aneurysms and aortic dissections; which are potentially deadly tears and ruptures in the aorta. 

The research was presented at the American Heart Association Scientific Sessions on November 17, indicating that testing on mice provides insight into the link between use of the popular antibiotics and aortic injuries.

Researchers from Baylor’s College of Medicine conducted tests on mice with normal or moderately stressed aortas, giving them either Cipro (ciproflaxin) or a placebo. Cipro belongs to a class of popular antibiotics known as fluoroquinolones, which also includes the widely used brand-name drugs Levaquin and Avelox.

The study found that mice with unstressed aortas appeared to be unaffected. However, 79% of mice with moderately stressed aortas developed aortic aneurysms or dissections, with 67% developing the more serious aortic dissections and 15% suffering fatal ruptures. Among those given a placebo, only 45% of those with stressed aortas were diagnosed with aortic aneurysm or dissection, with 25% developing dissections and none suffering ruptures.

According to the researchers’ findings, Cipro appeared to decrease the activity of an enzyme known as LOX, which helps stabilize the extracellular matrix. It also increased enzymes that led to extracelluar matrix degeneration and cell death.

Aortic aneurysm is a painful and potentially serious condition involving a bulge in the aorta, where the walls of the artery have weakened. They can cause severe chest pain, as well as carry the risk of rupturing. Aortic dissections are similar, but potentially more serious and life-threatening condition, involving degradation within the layers of the aorta. Both pose a serious health risk and usually require invasive surgery to treat.

In October 2015, a report published in the medical journal JAMA Internal Medicine found that current use of Levaquin, Avelox or other similar fluoroquinolone antibiotics was associated with a two-fold increased risk of suffering an aortic aneurysm or dissection injury. The research was conducted to examine whether the known risk of collagen degredation from fluoroquinolones, which causes the risk of tendon ruptures, may also cause problems with the aorta.

The FDA issued a major fluoroquinolone antibiotics warning on May 12, 2016, indicating that a variety of “disabling and potentially serious side effects” led the agency to conclude that the risks may outweigh the benefits associated with using the medications to treat uncomplicated infections.

That warning concerned reports of permanent nerve damage, known as peripheral neuropathy, as well as tendon ruptures and other health risks. However, the statement did not address concerns about the risk of aortic aneurysm and aortic dissection from the antibiotics, which emerged with the publication of an independent study months earlier.

In May 2017, the FDA issued another drug safety communication indicating that it found no link between Cipro and similar antibiotics and an increased risk of aortic aneurysm and aortic dissection. However, this latest study seems to provide some additional information about the potential link and biological mechanism.

There are currently hundreds of Levaquin lawsuits, Avelox lawsuits and Cipro lawsuits filed throughout the federal court system over side effects allegedly caused by the antibiotics, and a number of lawyers have also been investigating potential cases over the past two years for individuals diagnosed with an aortic aneurysm or dissection injury.