Antibiotic Associated with Sudden Death

The idea of a common antibiotic carrying fatal risks is unsettling, but new research shows that this might be the case for a small number of patients. A new study published in the New England Journal of Medicine (NEJM) on May 17 shows that Zithromax (azithromycin) can increase the risk of sudden death. The risk is low but relevant, particularly for those who have a history of heart problems, including:  

• Patients with heart failure or have had a previous heart attack
• Patients with diabetes
• Patients who have undergone bypass surgery
• Patients who have stents implanted

Zithromax, also referred to as Z-Pak, is used to treat bronchitis, pneumonia, sexually transmitted diseases (STDs) and bacterial infection in the ears, lungs, skin and throat. Oftentimes, it is preferred over other antibiotics due its short five-day treatment period.

Study Results

The study compared the rate of sudden death associated with various antibiotics among 540,000 Medicaid patients between ages 30 to 74 from 1992 to 2006. Lead author Dr. Wayne A. Ray and his team included 350,000 prescriptions for Zithromax, 1.4 million for amoxicillin, 265,000 for ciprofloxacin and 194,000 for levofloxacin in their study; these prescriptions were also compared to 1.4 million periods of no treatment. Overall, Zithromax had 64.6 million deaths per million courses, compared to 21.8 for amoxicillin and 24 for non treatment periods. While this demonstrates a link between Zithromax and sudden death, the exact causality remains uncertain.  

Finding Implications

The risk may not be overwhelming, but the study’s findings may be the deciding factor for some high-risk patients. Dr. Roy M. Gulick, chief of infectious diseases at New York-Presbyterian/Weill Cornell told the New York Times that, “in someone with significant cardiovascular risks or documented disease, the results of this study would be one factor that would help you choose among the antibiotics.”

FDA Reviewing Results

The U.S. Food and Drug Adminstration (FDA) addressed the study in a Safety Alert, issued the same day the study was published. The agency “is reviewing the results from this study and will communicate any new information on azithromycin and this study or the potential risk of QT interval prolongation after the agency has completed its review.” The FDA has recommended that patients and healthcare professionals be aware of the potential risks, but otherwise no new guidelines have been issued.