FDA Statement regarding azithromycin (Zithromax) and the risk of cardiovascular death

[05-17-2012] The U.S. Food and Drug Administration (FDA) is aware of the study published in the New England Journal of Medicine, on May 17, 2012, that compared the risks of cardiovascular death in patients treated with azithromycin (Zithromax), amoxicillin, ciprofloxacin (Cipro), levofloxacin (Levaquin), and no antibacterial drug. The study reported a small increase in cardiovascular deaths, and in the risk of death from any cause, in persons treated with a 5-day course of azithromycin (Zithromax) compared to persons treated with amoxicillin, ciprofloxacin, or no drug. The risks of cardiovascular death associated with levofloxacin treatment were similar to those associated with azithromycin treatment. FDA is reviewing the results from this study and will communicate any new information that results from the FDA review.
Patients taking azithromycin should not stop taking their medicine without talking to their healthcare professional.
Healthcare professionals should be aware of the potential for QT interval prolongation and heart arrhythmias when prescribing or administering antibacterial drugs. (See additional information below.)
Azithromycin belongs to a class of antibacterial drugs called macrolides, which have been associated with cardiovascular effects; specifically, prolongation of the QT interval. Prolongation of the QT interval can lead to torsades de pointes (TdP), an abnormal heart rhythm, which can be fatal. Azithromycin was the only macrolide examined in the published study; the study did not address other macrolide antibacterial drugs, such as clarithromycin (Biaxin) and erythromycin, regarding the potential for cardiovascular death.
In 2011, FDA reviewed macrolide drug labeling information related to QT interval prolongation and TdP. The WARNINGS AND PRECAUTIONS section of the Zmax drug label (azithromycin extended release for oral suspension) was revised in March 2012 to include new information regarding risk for QT interval prolongation, which appears to be low. The drug labels for clarithromycin and erythromycin also contain information about QT interval prolongation in the WARNINGS section. FDA is in the process of updating risk information in the drug labels for additional macrolide antibacterial drugs.
FDA-approved indications for azithromycin include:

Acute bacterial exacerbations of chronic pulmonary disease
Acute bacterial sinusitis
Community-acquired pneumonia
Pharyngitis/tonsillitis
Uncomplicated skin and skin structure infections
Urethritis and cervicitis
Genital ulcer disease

FDA will communicate any new information on azithromycin and this study or the potential risk of QT interval prolongation after the agency has completed its review.