The Food and Drug Administration warned consumers Friday against taking malaria drugs chloroquine and hydroxychloroquine to treat Covid-19 outside a hospital or formal clinical trial setting after “serious” poisoning and deaths were reported. The agency said it became aware of reports of “serious heart rhythm problems” in patients with the virus who were treated with the malaria drugs, often in combination with antibiotic azithromycin, commonly known as a Z-Pak. It also warned physicians against prescribing the drugs to treat the coronavirus outside of a hospital. “Hydroxychloroquine and chloroquine can cause abnormal heart rhythms such as QT interval prolongation and a dangerously rapid heart rate called ventricular tachycardia,” the agency wrote in the notice. “We will continue to investigate risks associated with the use of hydroxychloroquine and chloroquine for COVID-19 and communicate publicly when we have more information.” Patients taking the drugs for approved reasons, including malaria or to treat autoimmune conditions like Lupus, should continue taking their medicine as prescribed, the FDA said.