Azithromycin and other antibiotics play an important part in modern medicine but are often used inappropriately.

FORBES: FDA Issues New Warnings On Zithromax

Drug labels for azithromycin have been updated to include warnings about this risk, the FDA said.

CNN: FDA: Popular antibiotic can cause fatal heart rhythms

The warning is "not the result of adverse event reports related to azithromycin, " according to an FDA spokeswoman.

CNN: FDA: Popular antibiotic can cause fatal heart rhythms

The drug, azithromycin, sells under the name Zithromax or Zmax and is commonly sold in what's called a Z-Pak.

CNN: FDA: Popular antibiotic can cause fatal heart rhythms

Now for anyone on azithromycin, do not panic and do not stop taking your medication without talking with your doctor.

FORBES: The FDA Is Faster. Now Let's Make It Safer

In a well done study of patients covered by Tennessee Medicaid, scientists are reporting that azithromycin is associated with an increased risk of cardiovascular deaths.

FORBES: The FDA Is Faster. Now Let's Make It Safer

Ray told CNN it's unclear why azithromycin can cause heart issues.

CNN: FDA: Popular antibiotic can cause fatal heart rhythms

Azithromycin has been used for years primarily to treat respiratory infections, although it is probably overused, given that many respiratory infections clear up without antibiotics, and important bacteria are developing resistance.

FORBES: FDA Issues New Warnings On Zithromax

This is big news because azithromycin, sold by Pfizer as Zithromax and also available as a generic, is one of the most-used antibiotics because of its ease of use and effectiveness against a wide range of bacteria.

FORBES: The FDA Is Faster. Now Let's Make It Safer