While antibiotics can be life-saving, they can also cause harm.
In a study published today in the Journal of the American College of Cardiology, researchers at PHSA’s Therapeutic Evaluation Unit in partnership with the University of British Columbia (UBC) found that current users of fluoroquinolone antibiotics, such as Ciprofloxacin or Cipro, face a 2.4 times greater risk of developing aortic and mitral regurgitation, where the blood backflows into the heart, compared to patients who take amoxicillin, a different type of antibiotic. The greatest risk is within 30 days of use.
Fluoroquinolones are a class of antibiotics approved to treat or prevent certain bacterial infections like sinusitis or bronchitis.
While this class of antibiotics is convenient (it comes in the form of a once-a-day pill), most of the time, it’s not really needed.
“The Therapeutic Evaluation Unit at PHSA aims to evaluate different drugs and health technologies to determine whether they enhance the quality of care delivered by our programs or improve patient outcomes,” explains Dr. Bruce Carleton, director of the unit and research investigator at BC Children’s Hospital. “By leading this study with UBC, we’re highlighting the need to be thoughtful when prescribing antibiotics, which can sometimes have negative effects that are permanent or long-lasting. As a result of this work, we will continue working with the BC Antimicrobial Stewardship Committee to ensure the appropriate prescribing of this class of antibiotics to patients across British Columbia, and reduce inappropriate prescribing.”
For the study, scientists analyzed data from the U.S. Food and Drug Administration’s adverse reporting system as well as a massive private insurance health claims database in the U.S. that captures demographics, drug identification, dose prescribed and treatment duration. Researchers identified more than 12,000 cases of valvular regurgitation with 125,020 case-control subjects in a random sample of more than nine million patients. They defined current fluoroquinolone exposure as an active prescription or 30 days prior to the adverse event, recent exposure as within days 31 to 60, and past exposure as within 61 to 365 days prior to an incident. Scientists compared fluoroquinolone use with amoxicillin and azithromycin.
The results showed that the risk of aortic and mitral regurgitation, blood backflow into the heart, is highest with current use, followed by recent use. They saw no increased risk aortic and mitral regurgitation with past use.
“We’re hoping that this study, along with other studies, will demonstrate that antibiotics are not and should not be the go-to solution for infections,” says Dr. Carleton.
This study was funded by PHSA’s Therapeutic Evaluation Unit and the department of ophthalmology at UBC.