A study published on the use of hydroxychloroquine in Brazil to treat Covid-19 has found the drug ineffective, the latest blow to President Jair Bolsonaro's push for its widespread use, AFP reported.

The clinical trial, conducted at 55 hospitals across Brazil and published in the New England Journal of Medicine, tested whether hydroxychloroquine improved the condition of patients with mild to moderate cases of Covid-19, alone or in combination with the antibiotic azithromycin.