May 18, 2012 – The U.S. Food & Drug Administration (FDA) issued a warning today informing the public that a new study has identified an increase in cardiovascular death in patients being treated with a 5-day course of Zithromax (generic: azithromycin). The administration is currently in the process of evaluating the research, and will communicate any new information on the matter when it becomes available. The term ‘cardiovascular death’ refers to an unexpected death that occurs due to cardiac causes within a relatively short period of time in a person with known or unknown cardiac disease.
Zithromax Side Effects Update 3/12/13: Zithromax has recently been found to have the potential to cause abnormal changes in the electrical activity of the heart that may lead to a potentially fatal irregular heart rhythm. Patients at risk for developing Zithromax heart problems include those with known risk factors such as QT interval prolongation, low potassium or magnesium levels, depressed heart rate, or use of certain heart medications. Click here to learn more.
What’s the problem?
The new study, which was published in yesterday’s edition of the New England Journal of Medicine (NEJM), found a small but significant increase in cardiovascular deaths – as well as deaths resulting from any cause – in patients taking Zithromax compared to individuals being treated with amoxicillin, ciprofloxacin, or no drug at all.
Manufactured and marketed by Pfizer, Zithromax belongs to a class of antibacterial drugs called macrolides that have been associated with a cardiovascular side effect known as prolongation of the QT interval. Last year, the FDA reviewed macrolide drug labeling information related to QT interval prolongation and Torsades de pointes, a rare type of ventricular tachycardia that exhibits distinct characteristics on the electrocardiogram (ECG).
In March 2012, the WARNINGS AND PRECAUTIONS section of the Zmax drug label (azithromycin extended release for oral suspension) was updated to include information about the risk of QT interval prolongation, which appears to be relatively low. Biaxin (generic: clarithromycin) and the various brand names of erythromycin also contain information about QT interval prolongation in the WARNINGS section. The FDA is currently in the process of updating the warning labels of other drugs from the macrolide class.
The FDA is advising patients taking Zithromax not to discontinue treatment with the drug without first consulting their physician. Healthcare professionals should be aware of the potential for serious cardiovascular side effects before prescribing Zithromax or any other drug from the macrolide class.