(BBC) — Hydroxychloroquine did not prevent Covid-19 in a study of 821 participants who had been exposed to patients infected with the virus, according to research from the University of Minnesota Medical School.
The findings, published in the New England Journal of Medicine, are from the first large, controlled, clinical trial of the controversial drug, say local reports.
Study participants were sent either placebo or hydroxychloroquine pills and told to take them for two weeks.
Results showed that there was little difference in who developed Covid-19 symptoms.
“The take-home message for the general public is that if you’re exposed to someone with Covid-19, hydroxychloroquine is not an effective post-exposure preventive therapy,” said the lead author of the study, Dr David R Boulware, from the University of Minnesota, according to a New York Times report.
The anti-malarial drug has been repeatedly promoted by US President Donald Trump, who said he had taken it himself.