Two drugs that have been promoted by President Trump for use in treating the coronavirus are being linked to heart problems in international research. The Hill reports that a review by France's drug safety regulator turned up 43 "cardiac adverse effects" in COVID-19 patients treated with hydroxychloroquine, typically used to treat malaria. The agency reported 100 total cases of adverse reactions in patients treated with experimental drugs—82 of them serious, including four deaths—though only about half of these incidents were tied to hydroxycloroquine; the other half were linked to lopinavir-ritonavir, which is used to treat HIV. Meanwhile, a small study out of Brazil has been brought to a halt after patients given a higher dose of chloroquine, also used to treat malaria, developed heart arrhythmias, per the New York Times.
About half of the 81 patients involved in that study took 450mg of the drug two times a day for five days; the other half received 600mg for 10 days. Researchers started seeing irregular heart rates within three days in the patients given the higher doses; by the sixth day, 11 of them had died, and that portion of the study was ended. "Chloroquine causes a dose-dependent increase in an abnormality in the [electrocardiogram] that could predispose people to sudden cardiac death," says Dr. David Juurlink, who heads up the University of Toronto's clinical pharmacology division. Last month, Bloomberg reported that China had initially pushed using chloroquine after encouraging clinical trials, but that it soon walked that back after Wuhan Institute of Virology research showed just 2g of the drug—twice the recommended daily amount—proved deadly. (Read more chloroquine stories.)