(Reuters) – Malaria drug taken by US President Donald Trump to prevent COVID-19 has shown no benefit over placebo in reducing coronavirus infection in healthcare workers, according to clinical trial results published Wednesday.
The study largely confirms the results of a clinical trial in June that showed hydroxychloroquine to be ineffective in preventing infection in people exposed to the new coronavirus.
Trump started supporting hydroxychloroquine at the start of the pandemic and told reporters in May that he started taking the drug after two White House staff tested positive for COVID-19. Studies have shown that the drug offers little benefit as a treatment.
In the study of 125 participants, four who had taken hydroxychloroquine as a preventative treatment for eight weeks contracted COVID-19 and four on placebo tested positive for the virus.
According to findings published in the journal JAMA Internal Medicine, the eight were either asymptomatic or had mild symptoms that did not require hospitalization.
Research shows that routine use of the drug cannot be recommended among healthcare workers to prevent COVID-19, researchers from the University of Pennsylvania said.
The study authors said it was possible that a trial conducted in a community with a higher prevalence of the disease could detect a greater benefit of the drug.
In the last trial, which was halted before it could meet its goal of recruiting 200 participants, mild side effects such as diarrhea were more common in participants taking the antimalarial drug than in the placebo.