Zithromax Side Effects Linked To Increased Risk Of Cardiovascular Death: Study

A new study reignites concerns over the potential side effects of Zithromax, Z-Pak and similar antibiotics, finding that the widely prescribed drugs may increase the risk of heart problems and death.

Researchers from Kaiser Permanente indicate that they have found an association between the use of azithromycin-based antibiotics and death due to heart problems within just five days of exposure, according to a report published this month in the medical journal JAMA Network Open.

Azithromycin is an antibiotic that is popularly sold under brand names Zithromax, Z-Pak or Zmax, which is often used to treat certain bacterial infections, including ear infections, strep throat, pneumonia, traveler’s diarrhea, and certain other intestinal infections. It is one of the most widely used antibiotics, and is commonly prescribed to millions of Americans.

In this new report, researchers conducted a retrospective cohort study that looked at nearly eight million antibiotic exposures, including 1.7 million involving Zithromax, from December 2016 to March 2020. The study included patients ages 30 to 74.

According to the findings, Zithromax was linked to an 82% increased risk of cardiovascular death, but not sudden cardiac death, within five days of exposure. No increases were found six to 10 days after exposure. However, the rates of noncardiovascular death and all-cause mortality doubled when azithromycin users were compared to those given other antibiotics.

“These findings suggest that outpatient azithromycin use was associated with an increased risk of cardiovascular death and noncardiovascular death,” the researchers determined. “Causality cannot be established, particularly for noncardiovascular death, owing to the likelihood of residual confounding.”

The FDA issued a drug safety communication about Zithromax side effects in March 2013, warning that the antibiotic can cause serious and potentially fatal abnormal heart activity. The agency indicated at that time that Zithromax can disrupt the electrical activity of the heart, after completing an investigation into the risk of Zithromax heart issues that was started in May 2012.

A study published in the New England Journal of Medicine in early 2012 first warned about the potential Zithromax heart risks. Researchers found patients were 2.5 times more likely to die due to heart related problems on a five day Zithromax treatment when they compared it to treatment with other antibiotics or no antibiotic therapy.

Macrolides have been known to cause abnormal heart rhythm problems, including QT interval prolongation. These side effects can lead to a fatal heart condition, known as torsades de pointes.

Other studies have warned of more possible problems linked to the medications. In March 2015, a study published in PLOS One found that when pregnant women took macrolides, they were at an 80% increased risk of giving birth to a child born with cerebral palsy or epilepsy.

Another study, published in November 2015 by Chinese researchers, also linked Zithromax use to an increased risk of heart attacks.