On Tuesday the nation’s drug regulator said that the risk of heart problems resulting from a popular antibiotic is greater than previously thought.
Warning labels for azithromycin have advised patients that the drug can cause irregular heart beats in some patients — potentially leading to death — since last year. After reviewing a recent study of the drug, the U.S. Food and Drug Administration said it will required more explicit warnings to highlight the risk, the New York Times noted.
The study revealed that patients taking a five-day treatment regimen of azithromycin were slightly more likely to die compared to patients taking two other common antibiotics.
Used to combat bacterial infections, azithromycin is made by Pfizer (NYSE:PFE) under the Zithromax brand name, commonly known as Z-Pak. Generic versions are now available. The drug has been available to patients for two decades.
Azithromycin had been considered safer than the other drugs, erythromycin and clarithromycin. Those drugs have previously been associated with higher risks.
Shares of Pfizer rose fractionally in Wednesday morning trading.