MINNEAPOLIS — A large-scale study, co-authored by researchers at the University of Minnesota, Princeton and others around the world, found early treatment with ivermectin did not reduce the risk of hospitalization for patients with COVID-19.
The study, published Wednesday in the New England Journal of Medicine, is the largest yet to examine the effects of the drug used to treat parasitic worms in humans and livestock. Ivermectin became a popularized alternative treatment for COVID-19 in parts of the United States last year, despite warnings against its use by the World Health Organization and other medical professionals.
The double-blind, randomized, placebo-controlled drug trial looked at the effects of ivermectin on more than 3,500 COVID-symptomatic patients from 12 cities in Brazil from March to August 2021.
"Treatment with ivermectin did not result in a lower incidence of medical admission to a hospital due to progression of Covid-19 or of prolonged emergency department observation among outpatients with an early diagnosis of Covid-19," the authors wrote in their conclusion in the New England Journal of Medicine.
In addition, the study noted "no significant differences between the ivermectin group and the placebo group with regard to viral clearance at day 7," as well as "no significant differences" in clinical recovery time, risk of death, time of death, or number of days on ventilation.
The authors noted this trial included a larger number of participants than previous studies which showed inconsistent results or flawed methodology.
The study was attributed to more than two dozen researchers around the world, including Dr. David Boulware of the University of Minnesota, who is also conducting a separate large-scale trial of ivermectin at the U of M as part of the COVIDout study.
"As we actually get more and more better data, it's really time to move away from from this as a legitimate treatment," Dr. Boulware said. "In this case, like the trend was unfavorable, where they actually had more ER visits and hospitalizations than people given placebo ... In this case, there was really just no signs of benefit and it's really probably not an effective therapy."
RELATED: U of M: COVID treatment trial
Boulware said results of the U.S.-based COVIDout study are currently under review and should be published in the coming weeks. The National Institutes of Health is also studying ivermectin and other drugs on a large scale, and continuing to seek volunteer participants.
"I think really looking at the data and talking to your your local doctor about what may actually be beneficial for you, and what is the actual benefit and versus the risk of any medicine. I think that's important for any medical condition, COVID included," Dr. Boulware said.
WATCH: KARE 11 interviews Dr. David Boulware in January 2022: