Medical Scientists from University of Columbia have shown for the first time a link between fluoroquinolones, the most commonly prescribed classes of antibiotics and two types of heart problems. The study in partnership with the Provincial Health Services Authority's (PHSA) Therapeutic Evaluation Unit found that 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 prevalent within 30 days of use.
The study has been published in the Journal of the American College of Cardiology
, and calls are being made by the medical community in the US for the US FDA to consider new warning and labelling protocols.
Most doctors prefer fluoroquinolones over other antibiotics for their broad spectrum of antibacterial activity and high oral absorption, which is as effective as intravenous, or IV, treatment.
Lead author, Assoc Prof Dr Mahyar Etminan commented in a phone interview with Thailand Medical News "You can send patients home with a once-a-day pill. This class of antibiotics is very convenient, but for the majority of cases, especially community-related infections, they're not really needed. The inappropriate prescribing may cause both antibiotic resistance as well as serious heart problems."
The medical scientists from University of Columbia hope their study helps inform the public and doctors that if patients present with cardiac issues, where no other cause has been discovered, fluoroquinolone antibiotics could potentially be a reason.
Dr. Bruce Carleton, director of the unit and research investigator at BC Children's Hospital, a program of PHSA further commented "One of the key objectives of the Therapeutic Evaluation Unit is to evaluate different drugs and health technologies to determine whether they enhance the quality of care delivered by our programs or improve patient outcomes.
This study highlights the need to be thoughtful when prescribing antibiotics, which can sometimes cause harm. 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."
The medical scientists analyzed data from the U.S. Food and Drug Administration's adverse reporting system for this study. They also analyzed a massive private insurance health claims database in the U.S. that captures demographics, drug identification, dose prescribed and treatment duration. Researchers identified 12,508 cases of valvular regurgitation with 125,021 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 days to 12 months 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.
The team hopes that regulatory agencies would add the risk of aortic and mitral regurgitation to their alerts as potential side effects and that the results would prompt physicians to use other classes of antibiotics as the first line of defense for uncomplicated infections.
The same team had also in previous studies that had their results published in various other journals, discovered other heart issues associated with fluoroquinolones intake. Many leading medical institutions in the US in fact dissuade the usage of fluoroquinolones unless there are no other alternatives.
Reference: Mahyar Etminan et al, Oral Fluoroquinolones and Risk of Mitral and Aortic Regurgitation, Journal of the American College of Cardiology (2019). dx.doi.org/10.1016/j.jacc.2019.07.035