With 368 patients, the study is the largest look so far of hydroxychloroquine with or without the antibiotic azithromycin for Covid-19.

A malaria drug widely touted by President Donald Trump for treating the new coronavirus showed no benefit in a large analysis of its use in U.S. veterans hospitals. There were more deaths among those given hydroxychloroquine versus standard care, researchers reported.

The nationwide study was not a rigorous experiment. But with 368 patients, it’s the largest look so far of hydroxychloroquine with or without the antibiotic azithromycin for COVID-19, which has killed more than 171,000 people as of Tuesday.

The study was posted on an online site for researchers and has been submitted to the New England Journal of Medicine, but has not been reviewed by other scientists. Grants from the National Institutes of Health and the University of Virginia paid for the work.

Researchers analyzed medical records of 368 male veterans hospitalized with confirmed coronavirus infection at Veterans Health Administration medical centers who died or were discharged by April 11.

About 28% who were given hydroxychloroquine plus usual care died, versus 11% of those getting routine care alone. About 22% of those getting the drug plus azithromycin died too, but the difference between that group and usual care was not considered large enough to rule out other factors that could have affected survival.

Hydroxychloroquine made no difference in the need for a breathing machine, either.