The malaria drug hydroxychloroquine failed to protect healthcare workers caring for COVID-19 patients from becoming infected themselves, according to results of a formal, placebo-controlled trial published in Clinical Infectious Diseases.
The 1,483 participants worked in emergency departments, intensive care units, and other high-risk sites in the United States and the Canadian province of Manitoba. They were randomly assigned to receive hydroxychloroquine 400 mg, once weekly or twice weekly, for 12 weeks, or a placebo.
Compared to the risk of infection in the placebo group, the risk was 28% lower with once-weekly hydroxychloroquine and 26% lower with twice-weekly dosing. But those differences were not deemed to be statistically significant.
The University of Minnesota researchers point out that recruiting participants became difficult after potential adverse heart effects of the drug were publicized, and also that the hydroxychloroquine doses may have been too low.