In Brief

People are taking an animal deworming drug for COVID-19, and it's a really bad idea

Woman veterinary checking horse health in stable
(Image credit: DuxX/Getty)

People are taking dangerous doses of an anti-parasitic drug as a COVID-19 treatment, even though there is no solid evidence that it has any benefit for the disease.

The drug, called ivermectin, is often used to treat or prevent parasitic diseases in animals, such as heartworm, according to the Food and Drug Administration. In humans, some forms of the drug are used to treat parasitic worms, and a topical version of it is sometimes used to treat head lice.

But recently, misinformation about ivermectin has led some people to take the drug for COVID-19, even though it's not approved for this use. The idea of using ivermectin for COVID-19 arose last year when a study from researchers in Australia found that large doses of the drug showed activity against the novel coronavirus in lab dishes, The Washington Post reported. But studies in humans have been limited and showed mixed results. The Infectious Disease Society of America recommends against using ivermectin for COVID-19 outside of clinical trials.

Some people are taking veterinary forms of the drug because those formulations are easier to obtain than the ones prescribed for people, according to The Washington Post

That can have dangerous consequences: Veterinary forms of the drug meant for big animals, like horses and cows, come in very large doses that can be highly toxic for humans, according to the FDA. The agency says it has received multiple reports of people being hospitalized after self-medicating with a form of ivermectin meant for horses.

In humans, overdoses of the drug can cause nausea, vomiting, low blood pressure, allergic reactions, seizures, coma and even death, the FDA says. And even smaller doses of the veterinary drug can pose risks. That's because many inactive ingredients in animal medications haven't been studied for use in people, and these inactive ingredients could pose risks and affect how the drug is metabolized in humans, the FDA says.

Research on ivermectin continues, and the National Institutes of Health may study the drug as part of a clinical trial on repurposing older drugs for treating COVID-19, according to the Post. (However, the inclusion of ivermectin in that trial has not been confirmed, the Post reported.)

In the meantime, the FDA warns that taking a drug for an unapproved use can be dangerous and that people should never take drugs meant for animals.

Originally published on Live Science.  

Rachael Rettner

Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.