Plenty of unapproved, dubious, or downright dangerous COVID-19 treatments have come and gone over the past year, but the US Food and Drug Administration (FDA) has come out with a refresher warning after a number of people have fallen sick using horse deworming drugs to treat COVID-19.
The drug is ivermectin, a cheap and widely available medication used to treat parasite infestations. In humans, it’s used to treat head lice and scabies, as well as roundworms, and it’s also widely used on animals to treat parasitic worms. However, the products used to treat humans are different from the ones used on animals, which are often highly concentrated because they are used for large animals like horses and cows.
Recent months have seen a growing interest in using ivermectin to treat humans with COVID-19. All of this remains totally unverified for now, but it has already led to a number of people mistakenly taking horse dewormer in a bid to self-medicate against COVID-19.
“The FDA has received multiple reports of patients who have required medical support and been hospitalized after self-medicating with ivermectin intended for horses,” the FDA said in a statement.
Much of the hype around ivermectin and COVID-19 comes from a few studies that have suggested ivermectin inhibits the replication of SARS-CoV-2 in a petri dish. A very small clinical trial in January 2021 found that ivermectin did not prevent people from falling sick with COVID-19, but people who took the drug did tend to experience a mild cough and had a lower viral load. Overall, it’s still inconclusive.
The Infectious Disease Society of America advises against using ivermectin for COVID-19 outside of clinical trials. Merck, the pharmaceutical company behind Stromectol, a brand name of ivermectin, also says the medication should be used only for FDA-approved purposes, adding there’s “no meaningful evidence for clinical activity or clinical efficacy in patients with COVID-19 disease.”
The FDA noted that “some initial research” is looking into whether the drug could be used as COVID-19 treatment, but there is currently a lack of evidence to conclude it’s effective."
“People should not take any form of ivermectin unless it has been prescribed by a licensed health care provider and is obtained through a legitimate source,” the agency added. “Taking a drug for an unapproved use can be very dangerous. This is true of ivermectin, too.”
The buzz around ivermectin is reminiscent of hydroxychloroquine, an antimalarial drug that rose to prominence last year as a possible treatment for COVID-19. The drug was given a rocket boost when then-President Donald Trump revealed at a press conference he was taking hydroxychloroquine and azithromycin to ward off COVID-19, despite little evidence either worked.
Hydroxychloroquine became immensely politicized, but much of this hype ultimately fell flat and it never became the “game-changer” its supporters proclaimed it to be. Many clinical trials of hydroxychloroquine failed to show any real benefit in fighting COVID-19, while an influential study that sung its praise was eventually retracted. Sadly, reports of chloroquine poisoning and at least one death were reported after people began taking the drug, or in the death case, a version of it intended for fish, without doctor approval.
For more information about COVID-19, check out the IFLScience COVID-19 hub where you can follow the current state of the pandemic, the progress of vaccine development, and further insights into the disease.