In a report issued by the Federal Drug Administration (FDA), studies have shown that the popular and commonly-prescribed antibiotic, Azithromycin, may actually be a trigger for fatal, irregular heart rhythm for some patients it is prescribed for.
Prescribed under the names of Zithromax, Zmax, or the more familiar title "Z-Pack" is used to treat many bacterial infections such as pneumonia, bronchitis, and even ear infections. The warning issued by the FDA indicates a potential for the drug to cause abnormal changes in the electrical activity of the heart to occur that may, in turn, lead to a heart rhythm that could prove fatal.
Not all patients are at risk when using Zithromax. Those individuals that have been shown to be at higher risk are those patients that have been diagnosed with QT interval prolongation, low levels of potassium and magnesium, those presenting with a slower than normal heart rate, and those patients who are already taking prescriptions for abnormal heart rhythms or arrhythmias.
In an update that was issued by the FDA: “Health care professional should consider the risk of fatal heart rhythms with azithromycin when considering treatment options for patients who are already at risk for cardiovascular events.”
The update was issued as guidance by Pfizer, who in a study performed in May 2012, as well as another follow-up study, looked at the possible risk to the heart's electrical activity in those who were users of Azithromycin.
In one of the studies, performed in May 2012, funded by the National Heart, Lung and Blood Institute, data showed that per million course of treatment with Azithromycin, there were 47 extra heart-related deaths within taking a five day regimen of Zithromax, as opposed to the 10 day regimen of amoxicillin or another antibiotic.
The study also noted that the risks of death of a cardiovascular nature when using levofloxacin (Levaquin) were very similar to those that were associated with the use of Azithromycin.
Dr. Harlan Krumholz, of Yale University, said: “People need to recognize that the overall risk is low.” He went on to caution that more research is needed, but those patients with heart disease should not be encouraged to use Zithromax for now.
The FDA also weighed in on the studies, stating they were very aware of the findings and would review the data and update any new information.
According to the health care information company, IMS Health, Zithromax is one of the US' top-selling antibiotics, and sales of the drug consistently top $500 million or more each year.
So, what’s the verdict—you decide.
Should the use of Zithromax be halted until more is known of its overall effects?