A clinical trial is underway to evaluate whether the malaria drug hydroxychloroquine, given together with the antibiotic azithromycin, can prevent hospitalization and death from coronavirus 2019 (COVID-19). The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, the U.S. medical research agency, is sponsoring the trial. Teva Pharmaceuticals is donating medications for the study.

The trial will enroll approximately 2,000 adults across the country who have been infected with the virus that causes COVID-19 and are experiencing fever, cough and/or shortness of breath. Many will be 60 years of age or older or have serious complications such as cardiovascular disease or diabetes. Participants will be randomly assigned to receive short-term treatment with either hydroxychloroquine and azithromycin or matching placebos.

People with HIV (the virus that causes AIDS) and pregnant and breastfeeding women also are eligible to participate in the study, officials said.

As of mid-May, there were no treatments of COVID-19 approved by the U.S. Food and Drug Administration.

“We urgently need a safe and effective treatment. Repurposing existing drugs is an attractive option because these medications have undergone extensive testing, allowing them to move quickly into clinical trials and accelerating their potential approval for COVID-19 treatment,” Dr. Anthony S. Fauci, the director of NIAID. “Although there is anecdotal evidence that hydroxychloroquine and azithromycin may benefit people with COVID-19, we need solid data from a large randomized, controlled clinical trial to determine whether this experimental treatment is safe and can improve clinical outcomes.”

Effective May 13, the World Health Organization reported 4.1 million cases and 287,399 deaths from COVID-19 worldwide. That included the 1.3 million confirmed cases and 82,246 deaths in the United States.