Research suggests that patients on fluoroquinolones such as Levaquin may result in an increased chance of a tear in aorta walls, possibly resulting in aortic dissection.

Fluoroquinolones are a class of broad-spectrum antibiotics used to treat bacterial infections. These antibiotics are commonly prescribed to treat respiratory infections, urinary tract infections, bacterial bronchitis, and more. FDA approved fluoroquinolones include Levaquin, Avelox, Cipro, Factive, Noroxin, and Floxin.

Björn Pasternak, MD, PhD, senior researcher at the Clinical Epidemiology Unit T2 of the Department of Medicine Solna at the Karolinska Institute in Stockholm, and other researchers published a study in the BMJ showed that there was an increased risk of a tear in aorta walls in patients on fluoroquinolones such as Levaquin.

An aortic aneurysm is a small tear in aorta walls often caused by a weakness in the aortic wall. The tear can result in a bulging of the aortic wall. The pressure from blood flow on the tear in aorta walls can quickly result in an aortic dissection. An aortic dissection occurs when an aortic aneurysm widens and the tear in aorta walls spreads through all layers of the blood vessel. This results in profuse internal bleeding and can quickly prove fatal if not controlled.

Other research has suggested that fluoroquinolones such as Levaquin can cause collagen disorders. The aortic wall, made largely of collagen, can become weakened resulting in a tear in aorta walls. Research done in a new study shows that fluoroquinolone patients may be at risk for these events due to collagen affects.

The study analyzed data from 360,088 patients collected in Sweden between July 2006 and December 2013. Eligible patients were diagnosed with aortic aneurysms or aortic dissections within 60 days from the first fluoroquinolone treatment at a hospital, emergency department, or upon death due to the conditions.

Data analyzed by the researchers included patients on fluoroquinolones as the primary group of amoxicillin patients as a control group. During the first 60 days of treatment, 64 tear in aorta or dissection events were reported in the fluoroquinolone group. In the same period, 40 tear in aorta or dissection events were reported in the amoxicillin group.

A secondary study of days 61 through 120 showed that patients on fluoroquinolones continued to have an increased risk of a tear in aorta or dissection events when compared to the amoxicillin group. The most common type of an aneurysm in fluoroquinolone patients was an abdominal aortic aneurysm, with the second most common aneurysm being thoracic.

“There was a 66% increased rate of aortic aneurysm or dissection associated with oral fluoroquinolone use, compared with amoxicillin use, within a 60 day risk period from start of treatment,” the researchers stated in the study, according to Clinical Advisor. “Although the absolute risk increase was relatively small, it should be interpreted in the context of the widespread use of fluoroquinolones.”

The number of aortic events every year has increased steadily over the past few decades with an estimated 15,000 patients die each year of aortic aneurysm alone. Should aortic events be a direct side effect of Levaquin, the increased use of fluoroquinolones may account for the increased number of aortic events.