Heart Warning for Popular Z-Pack Antibiotic

The FDA issued a warning for the popular antibiotic (azithromycin) commonly known as a Z-Pack and sold under the brand names Zithromax and Zmax. This common antibiotic is widely used to treat sinus infections and bronchitis. In 2011 alone, there were over 50 million prescriptions for the Z-pack with sales in excess of 464 million dollars.

The FDA’s warning comes after a Vanderbilt study published in the New England Journal of Medicine in May 2012 which found a 2.5 fold higher risk of death from cardiac arrhythmia in the first five days of taking azithromycin when compared with another common antibiotic or no antibiotics at all. About 348,000 recorded prescriptions of azithromycin were compared with millions of similar records from people who were not treated with antibiotics or were treated with other antibiotics.

Specifically, the FDA safety announcement warned that azithromycin can cause abnormal changes in the electrical activity of the heart that may lead to a potentially fatal irregular heart rhythm. Patients at particular risk for developing this condition include those with known risk factors such as existing QT interval prolongation, low blood levels of potassium or magnesium, a slower than normal heart rate, or use of certain drugs used to treat abnormal heart rhythms, or arrhythmias. According to the FDA, the warning was a result of their review of a study by medical researchers as well as another study by a manufacturer of the drug that assessed the potential for azithromycin to cause abnormal changes in the electrical activity of the heart.

Pfizer, the manufacturer of Zithromax, issued a statement that “the majority of patients treated with Zithromax are not affected by this label update.” However, serious questions remain as to how long Pfizer has been aware of these deadly risks. Prior to the Vanderbilt study, the researchers noted well-documented reports in the published literature as FDA database reports linking azithromycin with serious arrhythmias. Based on this evidence, the Vanderbilt researchers sought to examine cardiovascular deaths in patients who were taking the antibiotic.

If you or a loved one was taking the antibiotic Zithromax or Zmax and suffered an abnormal heart rhythm, you may have a legal claim against Pfizer. You can contact our law firm for a free consultation at (610) 941-4204 or on our website: www.pbmattorneys.com