Increased Risk of Cardiovascular Death With Azithromycin and Levofloxacin

A study just released in The New England Journal of Medicine (NEJM) has found that azithromycin (ZITHROMAX, ZMAX) and levofloxacin (LEVAQUIN), two widely used antibiotics, may increase the risk of cardiovascular death, especially sudden death from heart rhythm disturbances.

Based on an examination of the medical records of 3.5 million Tennessee Medicaid patients, those who took azithromycin (distributed commonly as the five-day “Z-PAK”) were almost three times more likely to die from cardiovascular causes, such as sudden cardiac death, during the five days of therapy than those who took no antibiotics. The patients who took azithromycin also were 2.5 times more likely to die from cardiovascular causes than those who took amoxicillin (AMOXIL), another antibiotic. This translated to 47 to 245 more cardiovascular deaths (the range of excess deaths depends on the patients’ cardiac risk factors) for every 1 million patients placed on the drug, relative to amoxicillin users.

Levofloxacin was associated with a 50 percent increased risk of cardiovascular death compared to the risk in those who took amoxicillin, although the results for levofloxacin were less clear than those for azithromycin.

Based on this research and previous studies, both azithromycin and levofloxacin are thought to cause a heart rhythm disturbance known as torsades de pointes, which can lead to sudden cardiac death, the most common cause of death in azithromycin users in the recent NEJM study.

What You Can Do

Azithromycin and levofloxacin are used to treat a wide variety of bacterial infections. In 2010, more than 48 million prescriptions were written for azithromycin, and more than 9 million were written for levofloxacin. Unfortunately, many of these prescriptions were likely given unnecessarily for viral (as opposed to bacterial) infections, for which azithromycin, levofloxacin and other antibiotics are of no benefit. Levofloxacin and azithromycin are effective therapies to treat bacterial infections in some cases, but in many other cases, there are safer options.

In February, Public Citizen’s Health Research Group alerted Worst Pills, Best Pills News readers to the dangers of the overuse of antibiotics in children. As we mentioned that issue, antibiotics should be used only if there is a real suspicion of a bacterial infection for which the antibiotic is effective. The same applies to adults.

If you are generally healthy and have symptoms of an uncomplicated sinus infection or common cold, it is best to wait a few days for symptoms to pass on their own, because in most cases the infection is viral. (See the article “New Advice on Treating Sinus Infections With Antibiotics.”) If symptoms persist or worsen — or you have other concerning signs such as a persistent, high fever — an antibiotic can be considered after talking with your doctor. If use of an antibiotic is justified, your doctor should prescribe the most targeted therapy for your particular infection. That drug should be one with the fewest serious side effects.