'You are not a horse. You are not a cow': FDA issues blunt warning on taking ivermectin, drug promoted by Ron Johnson to treat COVID-19

For months, Republican U.S. Sen. Ron Johnson has been talking up the anti-parasitic drug ivermectin as part of a cocktail of repurposed drugs for early treatment of COVID-19.

Johnson's push even earned him a week-long suspension from YouTube.

On Saturday, the Food and Drug Administration issued a blunt warning for people not to use ivermectin to treat COVID-19.

The move by the FDA came amid reports that an increasing number of people in Mississippi and Louisiana were self-medicating with ivermectin intended for livestock. 

In Wisconsin, a handful of people have called UW Health in Madison after taking the drug for COVID-19, said Nasia Safdar, the health care system's director of infection control. Most experienced gastrointestinal side effects after taking the drug, and called because they were worried.

"I would say that we do not recommend it," Safdar said, "and it is a danger to use it."  

The FDA made much the same point in a tweet: "You are not a horse. You are not a cow. Seriously, y'all. Stop it."

Jonathan Yardley, an associate professor at Ohio State University College of Veterinary Medicine, said ivermectin is used to kill worms in horses and cows, but is quite powerful.

The drug has caused seizures in miniature horses and dogs, Yardley said, adding, "I find it strange that people are unwilling to take a vaccine that has been approved (under emergency use authorization), but are willing to take a horse drug. I just can't wrap my head around that."

Yardley said that the initial interest in ivermectin was triggered by a preprint that had not been peer-review, and was removed from the internet because of flaws in the data. 

There is no evidence that ivermectin will help treat or prevent COVID-19, said Amesh Adalja, a senior scholar at Johns Hopkins Center for Health Security. "The clinical data is very weak and there is no confidence in it."

Worse, Adalja said, some people are using the drug instead of getting vaccinated, and are taking the higher-dose veterinary ivermectin instead of the version that would be used to treat a human.

"I think the misinformation has been great," Adalja said, singling out Johnson's hearing for promoting a conspiracy that the drug is being suppressed.

He added: "I get some of the most voluminous amounts of hate mail every time I speak out against ivermectin."

The solution to the misinformation, he said, is to conduct a randomized, controlled study — the gold standard in drug testing. Such a trial is currently underway in England.

In an accompanying article titled, "Why You Should Not Use Ivermectin to Treat or Prevent COVID-19," the FDA declared it had "not approved ivermectin for use in treating or preventing COVID-19 in humans."

It also noted that ivermectin products for animals are different than products for humans.

"Ivermectin tablets are approved at very specific doses for some parasitic worms, and there are topical (on the skin) formulations for head lice and skin conditions like rosacea. Ivermectin is not an anti-viral (a drug for treating viruses)," the statement said, adding that "taking large doses of this drug is dangerous and can cause serious harm."

"If you have a prescription for ivermectin for an FDA-approved use, get it from a legitimate source and take it exactly as prescribed," the FDA added.

The FDA added that it "has not reviewed data to support use of ivermectin in COVID-19 patients to treat or to prevent COVID-19; however, some initial research is underway."

Also over the weekend, Johnson wrote a letter to federal health agencies not to rush the approval of COVID-19 vaccines.

On Monday, the FDA gave full approval to the Pfizer-BioNTech COVID-19 vaccine.

In a statement Monday, Johnson criticized the move.

"Expediting the approval process for the COVID-19 vaccine appears to primarily serve the political goal of imposing and enforcing vaccine mandates," he said. "Our federal health agencies have not been forthright with the public about how these life altering decisions have been made or what science and data they are based upon. This lack of transparency is unacceptable. The American people deserve full and accurate information so that they make up their own minds regarding vaccination."

Johnson, who tested positive for COVID-19 last October, has said he has not taken the vaccine.

In June, Johnson defended holding a news conference with five people who said they got side effects from taking the COVID-19 vaccine. During the event, Johnson said he was "pro-vaccine."

That same month, he received the week-long suspension from YouTube for comments he made during an appearance with the Milwaukee Press Club. Johnson mentioned hydroxychloroquine and ivermectin "for early treatment of COVID."

Earlier, the website removed two videos of doctors testifying about early therapies to COVID before the then-Johnson-led Homeland Security Committee.

One of the physicians who testified was Pierre Kory of Wisconsin. Johnson recently tweeted his support of Kory.

"Dr. Kory, with other medical professionals, had the courage and compassion to risk their lives treating Covid patients. Their reward: vilification, termination, censorship & lawsuits. We still need early treatment. Time for @NIH  (National Institutes of Health) to stop dragging its feet."