ST. LOUIS (KSDK) - If you've ever called the doctor after suffering a sore throat or sinus infection, chance are you've been prescribed an antibiotic.
Now there's a new warning about one of the world's best-selling antibiotics because it can cause a fatal irregular heart rhythm in some people.
The antibiotic is known as a Z-Pak, but its real name is azithromycin. Dr. Richard Lee, Chief of Cardiac Surgery at Saint Louis University Hospital joined First @ 4 to talk about the warning.
Click the video player above to learn more about Z-Paks.
KSDK