Taking hydroxychloroquine may not prevent COVID-19 after exposure
Hydroxychloroquine is no better than a sugar pill at stopping health-care workers and others exposed to COVID-19 from getting sick, the first results from a clinical trial testing the drug as a prophylactic suggest. In a study of 821 people who had been exposed to someone with a confirmed case of COVID-19, 11.8 percent of people taking hydroxychloroquine and 14.3 percent of people taking a placebo developed symptoms. There is no statistically meaningful difference in those numbers, researchers report June 3 in the New England Journal of Medicine. “This study definitely tempers enthusiasm for post-exposure prophylaxis among health-care workers,” says Rachel Hess, a primary care doctor and health services researcher at the University of Utah School of Medicine in Salt Lake City. She was not involved in the study, but is testing hydroxychloroquine in a clinical trial of people newly diagnosed with COVID-19. A far larger study of the drug’s potential to prevent disease, which involves thousands of health-care workers, is still ongoing and expected to report...