Another medication warning: Zithromycin

On March 12, 2013 the Federal Drug Administration issued a safety announcement regarding the popular antibiotic azithromycin (also known as Zithromax or Zmax). In part the statement read “…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 the use of certain drugs used to treat abnormal heart rhythms, or arrhythmias…” (www.fda.gov/Drugs/DrugSafety/ucm341822.htm).

The recommendation is largely based on a study which appeared in the May 12, 2012 issue of the New England Journal of Medicine in which they followed the outcomes of millions of patients enrolled in the Tennessee Medicaid program between 1992 and 2006.  They compared the frequency of cardiac events in patients who were on no antibiotics versus those who were on azithromycin, amoxicillin, ciprofloxacin or levofloxacin. Compared with amoxicillin or ciprofloxacin, azithromycin and levofloxacin were associated with an increased risk of cardiovascular deaths. To put this increase in perspective, however, there were 47 additional deaths per each one million courses of therapy-or a 1 in 21,276 chance.

FDA approved indications for azithromycin include acute exacerbations of chronic obstructive pulmonary disease (COPD), acute bacterial sinusitis, community acquired pneumonia, pharyngitis/tonsillitis, uncomplicated skin and skin structure infections, and certain sexually transmitted infections.

As always, it is important to put reports such as this in context.  All medications have side effects, and so any decision to take a medication needs to be weighed carefully---don’t say “its just an antibiotic” or “it’s just an aspirin”.  I have written previously regarding the overuse of all antibiotics (including azithromycin) for upper respiratory infections such as flu, bronchitis and sinusitis. In general these are either viral or self-limiting illnesses for which antibiotics have NO BENEFIT. If there is no benefit then the so-called risk:benefit ratio is infinite—i.e. all risk for no benefit. In that case, a 1 in 21,276 chance of a fatal side effect can and must be avoided. On the other hand, if you truly have a bacterial infection such as pneumonia, then antibiotic treatment is absolutely required and your physician—based on your individual health profile-will recommend the medication with the best risk:benefit ratio for you in that particular situation.

Patients often tell me they feel overwhelmed with reports such as this, and feel powerless to assure their safety when dealing with medication decisions.  Keep in mind, that azithromycin and other medications are usually very, very safe, but they are not risk free.  Proper use in the appropriate medical situation is always the guide.