Should I Be Taking Ivermectin for Covid-19?
The FDA-approved antiparasitic drug ivermectin is being touted as a possible treatment for Covid-19. But is this safe? Here's what the science says.
Ivermectin for Covid-19
A controversy very similar to the one that raged a year ago—about whether the drug hydroxychloroquine could prevent or treat Covid-19—is now surging around a different drug. The medication in question is the antiparasitic medication ivermectin.
Doctors are prescribing it. Patients are using it. Yet two recent studies suggest ivermectin has no effect, and the Food and Drug Administration (FDA) warns against using it to treat or prevent Covid-19.
Should you be taking ivermectin for Covid-19? (The answer to the hydroxychloroquine question, by the way, is “no.”)
What is ivermectin?
The FDA-approved ivermectin, first discovered in the late 1970s, is used to prevent and treat parasitic infections in both humans and animals. A pill can treat some parasitic worms in humans, and there’s a cream version for head lice and certain skin conditions like rosacea.
In animals, it’s used for heartworm (a parasitic roundworm that’s transmitted via an infected mosquito bite) and some parasitic infections.
Ivermectin is not approved for any viral infections, including Covid-19.
Some studies, like one published in June 2020 in Antiviral Research, have shown that ivermectin may beat back viruses, but this research was done in cell cultures, not humans.
Typically, that type of study is only “a first step in any drug-development cycle” and not the final word, says William Musick, PharmD, a clinical specialist in infectious diseases at Houston Methodist Hospital.
Most of these studies predated the current pandemic. So why is ivermectin getting so much attention now?
What’s the evidence for ivermectin and Covid-19?
In the Antiviral Research study, Australian researchers reported that ivermectin stopped SARS-CoV-2, the virus that causes Covid-19, from replicating. Again, this only looked at the virus in cell cultures and, adds Musick, at doses about 100 times higher than you would normally give a human.
Pierre Kory, MD, chief medical officer of Front Line Covid-19 Critical Care Alliance, which is a proponent of ivermectin, says that the drug “has been shown to work in numerous and increasing number of human trials.”
Some of those trials are randomized controlled trials, but many have not yet been peer reviewed, a key part of the research process. In peer review, other experts in the field scrutinize a study, helping to avoid bias and misinterpretation of results.
Other trials used ivermectin in combination with other drugs or had small sample sizes.
Recent trials of ivermectin for Covid-19
Two studies that have been peer reviewed showed no benefit of ivermectin in humans with Covid-19.
A large study published March 4 in JAMA randomized more than 400 adults with mild Covid-19 to receive ivermectin or a placebo for five days. In this study, ivermectin did not speed recovery.
In a much smaller study that appeared in The Lancet’s EClinicalMedicine on February 1, just 20 people with mild Covid-19 received either a single dose of ivermectin or a placebo within 72 hours of symptoms.
Seven days after treatment, there was no difference in the number of people who tested positive for SARS-CoV-2.
Is ivermectin safe?
The drug is generally considered safe, says Todd W. Rice, MD, associate professor of medicine and director of the Covid-19 intensive care unit at Vanderbilt University Medical Center in Nashville.
That’s as long as it’s being used for approved indications at approved doses. Recently, several patients have been hospitalized after using a form of ivermectin normally given to horses. (Medications for large animals like horses are more concentrated.)
And even when the same medication is used in animals and humans, the two dosage forms are not interchangeable. Medications made for animals are only approved for use in animals.
Even at human doses, ivermectin can interact with other medications, such as blood thinners. You can also overdose on the medication, and it sometimes causes nausea, vomiting, diarrhea, even seizures, and coma.
And there’s a lot of uncertainty when it comes to ivermectin and Covid-19. “We don’t know if it’s dangerous because we’ve never done it,” says Musick.
The bottom line on ivermectin
At best, ivermectin is unproven in relation to SARS-CoV-2, and it’s certainly not approved for this.
The National Institutes of Health says there’s not enough data to recommend ivermectin to prevent or treat Covid-19. Musick says he “would absolutely recommend against it.”
There’s still ongoing research on the use of ivermectin for Covid-19 treatment, including at the University of Liverpool in England, in conjunction with the global health agency Unitaid. The World Health Organization will conduct a deep analysis of this and future research.
Covid-19 treatment and prevention
Right now, there are some treatments for Covid-19, particularly for severely ill patients. These include the antiviral remdesivir, steroids, and the monoclonal antibody tocilizumab.
There is a gap in treatments for people who are sick but not sick enough to be in the hospital, says Dr. Rice. If it were found to be effective, ivermectin could fill this gap. “We don’t have an oral medicine that’s been shown to help with outpatients,” he says. Ivermectin has the advantages of being inexpensive and widely available.
For now, though, that gap remains.
As for Covid-19 prevention, even though vaccines are rolling out, expert advice is to keep doing what we’ve been doing: wear masks; avoid large gatherings, especially indoors; keep a safe, six-foot distance from others.
Next, curious about what it’s like to get the Covid-19 vaccine? Here are real Covid-19 vaccine stories.
- Food and Drug Administration: "Why You Should Not Use Ivermectin to Treat or Prevent COVID-19"
- Proceedings of the Japan Academy, Series B, Physical and Biological Sciences: "Ivermectin, 'Wonder drug' from Japan: the human use perspective"
- JAMA: "Effect of Ivermectin on Time to Resolution of Symptoms Among Adults With Mild COVID-19: A Randomized Clinical Trial"
- William L. Musick, PharmD, clinical specialist in infectious diseases, Houston Methodist Hospital
- Antiviral Research: "The FDA-approved drug ivermectin inhibits the replication of SARS-CoV-2 in vitro"
- Pierre Kory, MD, chief medical officer, Front Line COVID-19 Critical Care Alliance
- EClinicalMedicine: "The effect of early treatment with ivermectin on viral load, symptoms and humoral response in patients with non-severe COVID-19: A pilot, double-blind, placebo-controlled, randomized clinical trial"
- The Journal of the International Federation of Clinical Chemistry and Laboratory Medicine: "Peer Review in Scientific Publications: Benefits, Critiques, & A Survival Guide"
- Todd W. Rice, MD, associate professor of medicine and director of the Covid-19 ICU at Vanderbilt University Medical Center in Nashville
- National Institutes of Health: "Ivermectin"
- Unitaid: "Unitaid statement regarding Ivermectin as a potential COVID-19 treatment"