FDA, EMA Warn of Serious Side Effects of Hydroxychloroquine and Chloroquine

The FDA warned Friday of potential heart rhythm problems from the use of hydroxychloroquine and chloroquine as COVID-19 treatments.

The agency cited multiple reports of heart-related adverse events and deaths in COVID-19 patients taking the treatments either alone or with the antibiotic azithromycin. It noted that patients with heart and kidney diseases could be at an increased risk for the problems associated with the drugs.

The FDA noted that clinical trials are underway to evaluate the drugs for preventing and treating COVID-19 and that it has approved the drugs for emergency use for treating hospitalized COVID-19 patients.

The European Medicines Agency (EMA) has also warned of potential heart rhythm risks from the use of hydroxychloroquine and chloroquine as COVID-19 treatments.

The agency cited two recent clinical trials in Brazil and the UK that reported serious and sometimes fatal instances of heart rhythm problems in COVID-19 patients. The adverse events were mainly linked to high doses of the drugs and their use in combination with azithromycin.

“Clinical data are still very limited and inconclusive, and the beneficial effects of these medicines in COVID-19 have not been demonstrated. Results from large, well-designed studies are needed to make any conclusions,” the agency said.

The EMA noted that some clinical trials of chloroquine or hydroxychloroquine in COVID-19 patients are using higher doses than recommended for the drugs’ authorized indications, which increases the risk of side effects.