The antimalarial drug hydroxychloroquine did not benefit non-hospitalized patients with mild symptoms from Covid-19 who were treated early in their infection, according to a study to be published Thursday in the medical journal Annals of Internal Medicine.
Scientists from University of Minnesota launched the trial March 22 to see if the drug could decrease the severity of symptoms and prevent hospitalization. This was the first randomized clinical trial to study hydroxychloroquine in Covid-19 patients who weren’t hospitalized.
It was tested in 491 adults in the United States and Canada. Half the patients received a five-day hydroxychloroquine treatment and half the patients received five days of a placebo. The adults were enrolled within the first four days of reporting symptoms, and 56% were enrolled in the trial the first day they reported any symptoms. Doctors monitored symptoms for two weeks.
What the study found: At the end of two weeks, the study found that there was no advantage to taking the drug. About 24% of the hydroxychloroquine group had symptoms that persisted over 14 days, compared to the 30% who took the placebo. But hospitalizations were nearly the same — 2% of those in the hydroxychloroquine group were hospitalized, compared to the 3% taking the placebo. The death rate was identical for both groups, at 0.4%.
And, 43% of those who took hydroxychloroquine had side effects, compared to the 22% that took a placebo. Gastrointestinal symptoms were the most commonly reported side effect.
The study also found there was no benefit seen among people who took zinc or vitamin C along with the placebo or hydroxychloroquine.
The University of Minnesota researchers’ first randomized trial, published in the New England Journal of Medicine in June, looked at the drug as a possible post-exposure prophylaxis for adults who had been recently exposed to someone who was positive for Covid-19. It showed hydroxychloroquine did not prevent illness.
“Taken together, there is no convincing evidence that hydroxychloroquine can either prevent COVID-19 after exposure or reduce illness severity after developing early symptoms,” study author Dr. Caleb Skipper said in a statement. “While disappointing, these results are consistent with an emerging body of literature that hydroxychloroquine doesn’t convey a substantial clinical benefit in people diagnosed with COVID-19 — despite its activity against the coronavirus in a test tube.”
President Trump has called hydroxychloroquine a “game-changer” for treating patients with Covid-19, and said he took it himself to prevent infection, but several studies have found no benefits to treating Covid-19 patients with the antimalarial drug.
The US Food and Drug Administration revoked its emergency use authorization for both hydroxychloroquine and a related drug, chloroquine, for the treatment of Covid-19, saying the drugs are unlikely to be effective in treating the virus based on the latest scientific evidence. The National Institutes of Health announced last month it was halting its clinical trial of hydroxychloroquine for coronavirus patients.
One study published this month by researchers at Henry Ford Health System in Southeast Michigan found hydroxychloroquine increased hospitalized patients’ chances of survival. However, researchers not involved with the study were critical of it, saying it wasn't of the same quality of the previous studies that showed hydroxychloroquine did not help patients.