Widely Used Antibiotics Linked to Heart Risk

Macrolides linked to increased ventricular tachyarrhythmia, sudden cardiac death risk

/ Author:  / Reviewed by: Beth Bolt, RPh

(RxWiki News) A popular class of antibiotics used to treat common infections may carry some serious heart risks.

A new study from China found that macrolides — a group of antibiotics commonly used to treat bacterial infections like pneumonia, bronchitis and some sexually transmitted diseases (STDs) — may be linked to a small increased risk of ventricular tachyarrhythmia (a dangerously rapid heartbeat) and sudden cardiac death. Examples of macrolides include azithromycin (brand names Zmax, Zithromax), clarithromycin (Biaxin) and erythromycin (Ilotycin, T-Stat).

"The absolute risks of sudden cardiac death and cardiac death are small, so it should likely have limited effect on prescribing practice," said study author Su-Hua Wu, MD, PhD, of the Department of Cardiology at Sun Yat-Sen University in China, in a press release. "However, given that macrolides are one of the most commonly used antibiotic groups and millions of patients are prescribed these drugs annually, the total number of sudden cardiac deaths or [arrhythmias] may not be negligible."

Ventricular tachyarrhythmia (VT) is a fast heart rhythm that originates in the heart's lower chambers, called the ventricles. If left untreated, this condition can lead to serious complications and sudden death.

For this study, Dr. Wu and team used data from 33 other studies conducted between 1966 and 2015 to compare patients treated with macrolides to patients treated with other antibiotics and patients not treated with antibiotics. More than 20 million patients were involved in this analysis.

For patients not prescribed macrolides, an average 80 cases of VT per million treatment courses were found. By comparison, an additional 118 cases of VT and related sudden cardiac death per million treatment courses were found among patients prescribed macrolides in recent years.

Among these patients, 36 additional cases of sudden cardiac death from causes other than VT and 38 additional cases of non-sudden cardiac death per million treatment courses were also found.

No link was found between past macrolide use and increased cardiovascular risk, however. Macrolide use was also not linked to an increased risk of death from all causes.

In an editorial about this study, Sami Viskin, MD, of Tel Aviv University in Israel, put these numbers into perspective.

According to Dr. Viskin, these findings suggest that 1 in every 8,500 patients treated with a macrolide could experience a serious cardiac event, and 1 in every 30,000 patients might die as a result.

This study and editorial were published Nov. 9 in the Journal of the American College of Cardiology.

The National Natural Science Foundation of China funded this research. No conflicts of interest were disclosed.

Reviewed by: 
Review Date: 
November 10, 2015
Last Updated:
November 12, 2015