A randomized controlled trial published Thursday in the journal JAMA has revealed that Ivermectin does not speed recovery in people with mild cases of the disease. The study has taken everybody by surprise as this anti-parasitic drug was touted as a potential Covid-19 treatment.
The study suggests that there is little evidence about its efficacy against the coronavirus. Ivermectin is typically used to treat parasitic worms in both people and animals.
“Ivermectin is currently being used widely,” said Dr. Eduardo López-Medina, a doctor and researcher at the Center for Pediatric Infectious Diseases in Cali, Colombia, who led the new trial. “In many countries in the Americas and other parts of the world, it’s part of the national guidelines of treating Covid.”
Some studies have indicated that the drug can prevent several different viruses from replicating in cells. And last year, researchers in Australia found that high doses of ivermectin suppressed SARS-CoV-2, the virus that causes Covid-19, in cell cultures.
Such findings had spurred use of the drug against Covid-19, especially in Latin America.
In the new study, López-Medina and his colleagues randomly assigned more than 400 people who had recently developed mild Covid-19 symptoms to receive a five-day course of either ivermectin or a placebo. They found that Covid-19 symptoms lasted about 10 days, on average, among people who received the drug, compared with 12 days among those who received the placebo, a statistically insignificant difference.
The new trial adds much-needed clinical data to the debate over using the drug to treat Covid-19, said Dr. Regina Rabinovich, a global health researcher at Harvard’s T.H. Chan School of Public Health, who was not involved in the study.
But she noted that the trial was relatively small and did not answer the most pressing clinical question, whether ivermectin can prevent severe disease or death. “Duration of symptoms may not be the most important either clinical or public health parameter to look at,” she said.
The researchers did find that seven patients in the placebo group deteriorated after enrolling in the trial, compared to four in the ivermectin group, but the numbers were too small to draw a meaningful conclusion.
“There was a small signal there, and it would be interesting to see if that signal that we saw is real or not,” said López-Medina. “But that would have to be answered in a larger trial.”
The study population was relatively young and healthy, with an average age of 37 and few of the existing health conditions that can make Covid-19 more dangerous. Bigger trials, which are underway, could provide more definitive answers.
Ivermectin is a Food and Drug Administration (FDA)-approved antiparasitic drug that is used to treat several neglected tropical diseases, including onchocerciasis, helminthiases, and scabies.
It is also being evaluated for its potential to reduce the rate of malaria transmission by killing mosquitoes that feed on treated humans and livestock. For these indications, ivermectin has been widely used and is generally well tolerated.1,3 Ivermectin is not approved by the FDA for the treatment of any viral infection.