Research Wellness

Behind the research: is it safe to take fluoroquinolone antibiotics?

Recently, you may have heard about fluoroquinolones in the news. A class of antibiotics approved to treat certain bacterial infections, they’ve been in use for more than 30 years. Fluoroquinolones work by killing or stopping the growth of bacteria that can cause illness and infections. Without treatment, some of these infections can spread and lead to serious health problems.

In December 2018, the U.S. Food and Drug Administration (FDA) issued a warning to health care providers about the use of fluoroquinolones in certain higher risk groups, including those with hypertension, certain genetic conditions and the elderly.

So, what does this mean for you as a patient?

Dr. Nick Daneman, a clinician-scientist in infectious diseases at Sunnybrook, led a research study on fluoroquinolones that was published in 2015. It was one of the first to establish a link between the use of fluoroquinolones and an increased risk of aortic aneurysms, which can lead to dangerous bleeding or even death.

“There was strong anecdotal evidence that fluoroquinolones weakened the collagen in major tendons like the Achilles’, and we wanted to confirm that it did, in fact, lead to a higher risk of tendon injuries,” says Dr. Daneman.

“And then we thought, ‘is it possible that this medication impacts collagen in other areas, like the wall of the aorta (the largest artery in our body)?”

The results of the study were a resounding ‘yes’.

The researchers began by looking at the data of over 1.7 million Ontarians who turned 65 between April 1, 1997 and March 31, 2012; thirty-eight per cent of those people received at least one fluoroquinolone (including ciprofloxacin, norfloxacin, levofloxacin, moxifloxacin and ofloxacin) during that time period.

Of that patient group, the researchers found that 2.1% of them experienced tendon ruptures and 1.1% experienced aortic aneurysms. The risk of tendon rupture was tripled, and the risk of aortic aneurysm was doubled, during the time periods when patients were taking fluoroquinolones.

The connection between fluoroquinolones and aortic aneurysms was so strong that Dr. Daneman and his team were actually met with disbelief when submitting their research paper for publication.

“One editor kept asking us to send more and more supporting documentation, because he couldn’t believe that an association this strong hadn’t been noticed for so long,” says Dr. Daneman.

“But no matter how you looked at it, the evidence was clear: patients who were taking or had recently taken fluoroquinolones were at a higher risk of tendon or aorta rupture.”

Dr. Daneman and his team’s findings were so strong, their research was cited in the 2018 warning issued by the FDA.

However, this doesn’t mean that fluoroquinolones should never be used – even though they issued a warning, the FDA still recommends prescribing fluoroquinolones to those higher risk patients when no other treatment options are available.

Dr. Daneman agrees that there is still a place for fluoroquinolones, and that they remain a valuable treatment option for many patients.

“If a patient is ill with an infection, fluoroquinolones remain one of the important weapons in your treatment arsenal,” he says.

“As with any area of medicine, clinicians just have to make sure they weigh the risks against the benefits to make the best choice for their patients.”

About the author

Sybil Millar

Sybil Millar

Sybil Millar is the Communications Advisor for Infection Prevention and Control, Infectious Diseases, the Ross Tilley Burn Centre and the Critical Care program at Sunnybrook.

Have a question about this post? Get in touch.