What’s the problem with azithromycin?

Studies show that azithromycin can cause abnormal changes in the electrical activity of the heart that may lead to a potentially fatal irregular heart rhythm, or arrhythmia, which can lead to a heart attack.

The New England Journal of Medicine (NEJM) said in May 2012 that their research indicated “a small absolute increase in cardiovascular deaths” in persons treated with a five-day course of azithromycin compared to patients treated with other antibiotics. The FDA issued a “drug safety communication” about azithromycin in March 2013 that cited the NEJM study as well as a study by Pfizer.