Two epidemiologic studies were published in November 2015 linking the use of fluoroquinolones and aortic dissection and aneurysms, each major, life-threatening disorders.
First, Daneman et al, followed 657,950 patients an epidemiological study in order to “confirm the association of fluoroquinolones and tendon rupture, to clarify the potential association of fluoroquinolones and retinal detachment, and to test for a potentially lethal association between fluoroquinolones and aortic aneurysms.” The 657,950 patients received at least one fluoroquinolone during follow-up, amounting to 22,380,515 days of treatment. 18,391 patients developed aortic aneurysms for a statistically-significant adjusted hazard ratio of 2.24 (95% CI 2.02 – 2.49), consistent with an 124% increased risk for aortic aneurysms.
Also published in November was a case-control study by Lee et al. These researchers noted that “…fluoroquinolones have been associated with collagen degradation raising safety concerns related to more serious collagen disorders with use of these antibiotics”. They conducted a nested case-control analysis of 1,477 case patients and 147,700 matched control cases from Taiwan’s National Health Insurance Research Database from among 1 million individuals observed from January 2000 through December 2011.
Lee et al. confirmed the findings of Daneman et al., noting that the current use of fluoroquinolones was found to be associated with increased risk for aortic aneurysm or dissection with a statistically significant rate ratio of 2.43 (95%CI, 1.83-3.22. The current risk denotes a statistically significant 143% increased risk while the past usage risk was 48%, also statistically significant.
The importance of these two studies cannot be overstated. As described within the Practice Area of our site, animal and human studies have established that the fluoroquinolones ‘up-regulate’, or increase, within the body enzymes known as matrix metalloproteinases whose job includes breaking down collagen. Collagen is the most common protein within the body and gives structures such as tendons and ligaments their strength. The up-regulation of MMPs can result in the degradation or weakening of not only collagen but the ‘glue-like’ material found within the tendons’ cells, material known as the extracellular matrix or ECM. With the degradation of collagen and the ECM the tendon is weakened and may rupture. This condition is widely accepted within the medical and scientific communities and, in fact, the fluoroquinolones carry a ‘Black Box Warning’, the highest form of warning within a Product Insert, warning of tendon ruptures and tendonitis with the drugs.
However, collagen and ECM is also responsible for the strength of the aortic wall. The aorta is the largest artery in the body, coming out of the heart and transverse down the thorax and abdomen providing blood all the other blood vessels within the body. As the aortic wall is weakened as a result of the up-regulation of MMPs by the fluoroquinolones and collagen and the ECM dissolve the wall can balloon out; a condition known as an aneurysm. If the inner wall, but not the out wall, of the aorta ‘rips’, blood can escape the aorta into this space between the inner and out walls and migrate up and down the aorta, a condition known as an aortic dissection’.
Aortic aneurysms were the primary cause of 10,597 deaths and a contributing cause in more than 17,215 deaths in the United States in 2009.1 This number is likely an underestimation, because approximately 5% of the 200,000 people who die of sudden death each year may have abdominal aortic aneurysm as the cause.2
Dr. Restaino, through his work with SONAR, was amongst the first attorneys in the country to recognize this potentially lethal association between the fluoroquinolones and aortic disorders and the Restaino Law Firm is currently involved in the representation of individuals and/or surviving family members affected by adverse drug event.
 Schermerhorn M. A 66-year-old man with an abdominal aortic aneurysm: review of screening and treatment. JAMA 2009;30218:2015-22.