Study finds ivermectin ‘useless’ against Covid-19

The drug popularised as a treatment for Covid-19 by podcast host Joe Rogan is “useless” against the disease, a major new study has found.

Ivermectin, the anti-parasitic drug popularised as a treatment for Covid-19 by podcast host Joe Rogan, is “useless” against the disease, a major new study has found.

Researchers with the TOGETHER study, a worldwide project involving a series of clinical trials designed to test the effectiveness of several repurposed drugs to treat Covid-19, conducted a double-blind, randomised, placebo-controlled trial involving 3515 patients at clinics in Brazil.

Patients who had had symptoms for up to seven days and at least one risk factor were randomly assigned to receive ivermectin or a placebo, with 679 people in each group – 2157 received another intervention.

Those who received ivermectin were given a dosage of 400 micrograms per kilogram of body weight, once daily for three days.

“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,” concluded the paper summarising the findings, published this week in the New England Journal of Medicine.

The TOGETHER researchers noted that evidence supporting the role of ivermectin for treatment of Covid-19 was “inconsistent”.

“At least three meta-analyses of ivermectin trials have strongly indicated a treatment benefit, and others have concluded that there was no benefit,” they wrote.

“Although the number of included trials involving outpatients varies among the meta-analyses, the overall number of events that occurred in our trial is larger than the number of all the combined events in these meta-analyses. The results of this trial will, therefore, reduce the effect size of the meta-analyses that have indicated any benefits.”

Speaking to the Brisbane Times on Thursday, co-author Craig Rayner from drug development company Certara said the TOGETHER trial had comprehensively analysed ivermectin for any potential benefit.

“We found that treatment with ivermectin did not reduce the need for medical admissions to hospital settings for Covid-19 patients,” he said. “We examined it from multiple angles, multiple sub-group analyses, and ultimately, there is no suggestion of important clinical efficacy from ivermectin on Covid-19.”

Podcast host Joe Rogan. Picture: Supplied

Dr Rayner said he hoped the research would put the issue to bed once and for all.

“There are more than 80 randomised trials of ivermectin,” he said. “Meta-analyses with the low-quality and fraudulent studies removed have shown that ivermectin doesn’t have a treatment benefit. I think, overall, the body of knowledge does not support any use of ivermectin for treating Covid-19 at any stage of the disease.”

In the UK, the large-scale PRINCIPLE study – Platform Randomised Trial of Treatments in the Community for Epidemic and Pandemic Illnesses – announced in June 2021 it would be adding ivermectin.

That trial is ongoing. Researchers from PRINCIPLE did not immediately respond to a request for comment.

Health experts have taken to social media to weigh in on the latest study.

Dr Eric Topol from the Scripps Research Institute wrote on Twitter, “Ivermectin: the largest randomised, double-blind trial yet conducted, with early treatment, indicates there is no difference compared with placebo. It doesn’t work. Period.”

Victoria’s chief health officer Brett Sutton wrote, “No, ivermectin doesn’t have good evidence that it works. But we’ve got molnupiravir on the PBS for those at risk of severe illness. And Paxlovid also TGA approved. Both with real efficacy for those most at-risk.”

Professor Greg Dore from the UNSW’s Kirby Institute said, “TOGETHER study shows we can all say ivermectin is useless for Covid.”

But Dr Peter McCullough, a cardiologist who has criticised Covid-19 vaccines and promoted alternative treatments including ivermectin, said the TOGETHER trial was “too small” and “under-powered” and that three days was too short.

“Standard of care practice now at 600 micrograms for longer duration with four to six additional drugs,” he wrote.

Ivermectin first began to be touted as a therapeutic for Covid-19 in early 2020 after scientists in Melbourne found it could inhibit SARS-CoV-2 in the lab in high doses.

It then began to gain popularity as a treatment among some doctors and the likes of Rogan – who attributed his rapid recovery after catching the virus to a cocktail of medications including ivermectin – even as health authorities and the drug’s manufacturer Merck warned against its use, citing lack of evidence.

Last month, billionaire Clive Palmer said he likely “would have died” without a cocktail of anti-viral drugs including ivermectin and hydroxychloroquine after catching Covid-19 in February.

Ivermectin has not been proven to treat Covid-19. Picture: The Pulse

Mr Palmer, who is unvaccinated, contracted the more deadly Delta variant in Sydney and was rushed to Pindara Hospital on February 27.

He told Sky News Queensland editor Peter Gleeson he was recommended the drugs by a team of specialists who treated former US President Donald Trump.

“I would have died otherwise, without doubt,” Mr Palmer said.

In September, Australia’s Therapeutic Goods Administration banned doctors from prescribing ivermectin off-label.

General practitioners are now only able to prescribe ivermectin for TGA-approved conditions, such as scabies and certain parasitic infections.

Ivermectin was first discovered in 1975 and came into medical use in 1981. It was approved for human use in 1988.

In 2015, half of that year’s Nobel Prize in Physiology or Medicine was awarded jointly to ivermectin’s discoverers, Satoshi Ōmura of Kitasato University and William Campbell of Merck.

The medication is sold in both human and animal formulations.

Veterinarians use it to deworm domestic animals and cattle.

For humans, it exists in tablet form and has been widely used in Africa to treat intestinal strongyloidiasis and onchocerciasis – also known as river blindness – which are conditions caused by parasitic worms.

Topical formulations are also used to combat head lice and skin conditions such as rosacea.

When the medication is taken as intended it is low risk – however, when taken in large doses it can cause serious side effects including severe nausea and vomiting, and neurological effects such as dizziness, seizures and coma.

In August last year, the US Food and Drug Administration told Americans to stop taking the drug by referencing the veterinary version.

The FDA said it had seen a rise in reports of patients being hospitalised after self-medicating with ivermectin.

“You are not a horse. You are not a cow. Seriously, y’all. Stop it,” the FDA tweeted.