Macrolide Antibiotics: Safe for the Heart?

Macrolide antibiotics may not increase heart arrhythmia risk

/ Author:  / Reviewed by: Beth Bolt, RPh

(RxWiki News) It was previously unknown whether macrolide antibiotics increased the risks of heart arrhythmia, a serious heart rhythm disturbance that can lead to death. New research is now bringing more clarity to this issue.

In spite of recent concerns, a new study from Canada found that macrolide antibiotics are likely not tied to an increased risk of serious heart arrhythmia or death.

Macrolide antibiotics — such as azithromycin (brand name Zithromax), clarithromycin (Biaxin) and erythromycin (EES, ERY-C, Erythrocin and others) — are commonly prescribed to treat respiratory tract infections. In 2010, an estimated 57 million prescriptions for macrolide antibiotics were written in the US alone.

Previous studies had conflicting findings on macrolide antibiotics and their potential link to heart arrhythmia and death. Because of this, the US Food and Drug Administration (FDA) issued a warning for the drugs in 2013.

Heart arrhythmias occur when the electrical impulses that control heartbeats don't work properly, causing the heart to beat too fast, too slow or irregularly.

To investigate the relationship between macrolide antibiotics and heart arrhythmia, researchers looked at more than 600,000 adults over the age of 65 from Ontario, Canada. Fifty-seven percent of these participants were women and 43 percent were men.

Researchers matched study participants according to age, health status and other factors. One group took macrolide antibiotics. The other took non-macrolide antibiotics.

The results showed that macrolide antibiotics were not tied to an increased risk of heart arrhythmia when compared to non-macrolide antibiotics.

Lead study author Amit Garg, MD, director of the ICES western facility in London, said in a press release, "We observed that, compared with non macrolide antibiotics, new use of macrolide antibiotics was associated with a similar 30-day risk of ventricular arrhythmia ... and a slightly lower risk of all-cause mortality."

He continued, "Nonetheless, these findings should be interpreted with caution, and physicians should always consider a patient's baseline risk for adverse events before prescribing macrolides or other antibiotics."

If you have any questions regarding the risk factors tied to macrolide antibiotics, talk to your doctor or pharmacist.

This study was published Feb. 22 in the Canadian Medical Association Journal.

No funding sources or conflicts of interest were disclosed.

Reviewed by: 
Review Date: 
February 24, 2016
Last Updated:
February 25, 2016