Common Type Of Antibiotic May Lead To Heart Problems

Current users of fluoroquinolone antibiotics may face a 2.4 times greater risk of developing mitral and aortic regurgitation, wherein blood backflows into the heart with the risk being the greatest within 30 days of use, compared to those taking another type of antibiotic, such as amoxicillin, according to the researchers. 

Fluoroquinolone antibiotics are favoured by some physicians due to their broad spectrum of antibacterial activity and high oral absorption, however fluoroquinolone antibiotics have also been linked to other heart problems in recent studies.

"You can send patients home with a once-a-day pill," said Mahyar Etminan, lead author and associate professor of ophthalmology and visual sciences in the faculty of medicine at UBC. "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."

"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," said Dr. Bruce Carleton, director of the unit and research investigator at BC Children's Hospital, a program of PHSA. "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."

Data was analyzed from the US FDA adverse reporting system and a private American insurance health claims database; 12,505 cases of valvular regurgitation were identified with 125,020 case control subjects in a random sampling of some 9 million patients. Current fluoroquinolone exposure was defined as being an active prescription or 30 days prior to the adverse event, recent exposure was defined as being within 31-60 days, and past exposure was defined as being within 61-365 days prior to an incident. Fluoroquinolone antibiotic use was compared to use with amoxicillin and azithromycin.

Risk of aortic and mitral regurgitation blood backflow into the heart was found to be highest with current use of fluoroquinolone antibiotics followed by recent use of this type of antibiotic, with no increased risk being seen in past use. Findings are hoped to be confirmed in other studies and that the results may prompt physicians to use other classes of antibiotics as the first line defense for uncomplicated infections over fluoroquinolone antibiotics.