MINNEAPOLIS (WCCO) — There’s new warning about a popular antibiotic you might have taken.

The Food and Drug administration says azithromycin, known as the Z-Pak, can cause a potentially deadly heart problem.

They say the drug could cause an irregular heart rhythm that could be especially dangerous for patients who’ve had a prior heart attack, angina or chest pain.

The antibiotic is used to treat many kinds of infections including pneumonia and tonsillitis.

The FDA says doctors should be aware of the risk factors before prescribing the Z-Pak to patients.