Leo Sher, M.D.

The U.S. Food and Drug Administration (FDA) has notified healthcare professionals of a new study (1) reporting a small increase in cardiovascular death, and in the risk of death from any cause, in patients treated with a 5-day course of azithromycin (Zithromax; Pfizer) compared to individuals treated with amoxicillin, ciprofloxacin, or no drug.

During the study period, there were 347,795 prescriptions for azithromycin, 1,348,672 for amoxicillin, 264,626 for ciprofloxacin, and 193,906 for levofloxacin. In addition, the researchers identified 1,391,180 controls not given antibiotics. During the 5-day course of azithromycin treatment, there were 29 deaths from cardiovascular causes, with 22 being sudden cardiac death.

Azithromycin belongs to a class of antibacterial drugs called macrolides, which have been associated with cardiovascular effects; specifically, prolongation of the QT interval. Healthcare professionals should be aware of the potential for QT interval prolongation and heart arrhythmias when prescribing or administering macrolides.

Zithromax is indicated for mild to moderate susceptible infections including acute bacterial exacerbations of COPD, acute bacterial sinusitis, acute otitis media, community-acquired pneumonia, pharyngitis/tonsillitis, uncomplicated skin and skin structure infections, urethritis, cervicitis, chancroid in men, and Mycobacterium avium complex (MAC) disease.

1.    Ray WA, Murray KT, Hall K, Arbogast PG, Stein CM. Azithromycin and the risk of cardiovascular death. N Engl J Med. 2012 May 17;366(20):1881-90.