(ABC News)--An antibiotic used to treat common infections may carry serious heart risks, according to a new warning from the U.S. Food and Drug Administration.
The drug, called azithromycin but sold under the brand names
Zithromax and Zmax as Z-Pak capsules, is prescribed for infections of
the ears, lungs, sinuses, skin, throat, and reproductive organs,
according to the FDA. But the antibiotic can interfere with the heart's
electrical activity, disturbing its rhythm with potentially fatal
consequences.
"Health care professionals 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 FDA said in a statement.
Elderly people and those with irregular heart rates, arrhythmias, and
low blood levels of potassium or magnesium are at a particularly high
risk for the deadly heart condition, according to the FDA.
The warning comes 10 months after a study published in the New England Journal of Medicine
found a small increase in cardiovascular deaths among people treated
with Zithromax compared to those given the antibiotics amoxicillin or
ciprofloxacin or no treatment at all. At the time, the FDA urged patients
taking Zithromax to "not stop taking their medicine without talking to
their healthcare professional" — a recommendation that stands today,
despite the new warning.
Zithromax, made by Pfizer, comes in tablet and liquid form and is
usually taken for up to five days. The drug's labels have been updated
to strengthen the warnings and precautions section.
"Patient safety is of the utmost importance to Pfizer and we
continuously monitor the safety and efficacy of our products to ensure
that the benefits and risks are accurately described in the product
label, as approved by the FDA," Pfizer said in an email statement to
ABCNews.com. "Zithromax (azithromycin) has had a well established
benefit risk profile for more than twenty years and continues to be an
effective treatment option for patients all over the globe suffering
from many types of bacterial infections."
Pfizer noted that the majority of patients treated with Zithromax "are not affected by this label update."
While alternatives to Zithromax are available, the FDA warned that
they, too, can carry "other significant side effects that should be
considered when choosing an antibacterial drug."
People taking Zithromax should seek immediate medical care in the
event of an irregular heartbeat, shortness of breath, dizziness or
fainting, the FDA said.
Copyright 2013 by ABC News
