Australia’s Therapeutic Goods Administration said the agency will take a close look at whether fluoroquinolone antibiotics—including ciprofloxacin, norfloxacin and moxifloxacin—are causing potentially dangerous heart conditions.

TGA noted reports that fluoroquinolone antibiotics may be responsible for aneurysms in the aorta, which can cause tears or ruptures, which in turn can lead to severe internal bleeding and even death.

“We are liaising with international counterparts and will investigate to see what regulatory action should be taken in the local context,” the agency said. No Australians have reported any aortic aneurysms.

It’s the second time through the regulatory wringer in as many years for the potent antibiotics. Last summer, the FDA strengthened prescribing information on the drugs after reports that they were causing adverse mental health and blood sugar side effects.