Recently the world has been treated to a flood of misinformation about ivermectin, an anti-parasitic drug that some people thinks can treat or prevent the Covid-19 virus.
It can’t, but that hasn’t stopped a variety of Fox News hosts, including Sean Hannity, Tucker Carlson, and Laura Ingraham, from pushing it for months. As a result, prescriptions for ivermectin have increased like crazy. Here’s a chart just released by the CDC, showing the weekly number of prescriptions over the past two years:
As you can see, the numbers shot up at the beginning of this year, to 40,000 prescriptions per week, and this past month they shot up again, to over 80,000 per week. All this ivermectin has had no effect at all on Covid-19 infections, which have continued to rise, but that hasn’t stopped people from desperately trying to get ivermectin.
Ivermectin doesn’t work. It doesn’t prevent Covid-19, nor does it treat it. Unfortunately, the official government response to this misinformation has once again failed to be blunt enough, with a few exceptions. More on that below, but first let’s review what the heck ivermectin is.
Ivermectin is used to treat two relatively rare (in the U.S.) parasites: a nematode called Onchocerca volvulus that causes river blindness, and an intestinal nematode called Strongyloides stercoralis. (Both of these are sometimes called worms, but they are microscopic in size, and unrelated to the worms that most people are familiar with.) Nematodes are not even remotely similar to viruses, and there’s no reason to think that a treatment for nematode infections will cure a virus–unless, apparently, a popular talk show host claims that it will.
Ivermectin also used for de-worming livestock such as cows and horses, which means that veterinarians carry supplies of ivermectin, often in very large doses. The veterinary form is available in a paste that you can feed to animals. This has resulted in a number of people buying and consuming large amounts of ivermectin–or, as one person put it, “eating horse goo from the tractor store.” This does not usually end well.
Here’s an example from the CDC’s latest health advisory:
An adult drank an injectable ivermectin formulation intended for use in cattle in an attempt to prevent COVID-19 infection. This patient presented to a hospital with confusion, drowsiness, visual hallucinations, tachypnea [abnormally rapid breathing], and tremors. The patient recovered after being hospitalized for nine days.
So: not good. This case and others prompted the FDA to tweet, in a rare instance of bluntness: “You are not a horse. You are not a cow. Seriously, y'all. Stop it.”
The FDA also issued a news release explaining why people should not use ivermectin to treat or prevent Covid-19, and especially not to use doses designed for large animals. It’s dangerous, as the case cited by the CDC illustrates.
Where did this interest in ivermectin begin? Just a couple of days ago, NBC News reporter Ben Collins put together an excellent Twitter thread explaining some of the recent history. One of the main sources was a sketchy group called America’s Frontline Doctors, which was founded by an anti-vaxxer named Simone Gold, who as Collins explained “spent the last year barnstorming churches and schools, insisting COVID vaccines cannot be trusted.”
Despite its name, America’s Frontline Doctors is most definitely not working on the “front lines” treating patients, but instead is a right-wing political organization known primarily for spreading Covid-19 misinformation. Last year they promoted hydroxychloroquine as a Covid-19 treatment, which didn’t work. More recently, they have been offering online consultations to people who wanted ivermectin. The consultations cost $90, which didn’t include the cost of the medicine, but they’d connect you to a pharmacy that would deliver it.
(Aside: in an interesting twist, Simone Gold has been indicted and is now awaiting trial for her role in the January 6 insurrection at the U.S. Capitol in Washington, D.C.)
So here we are: 80,000 prescriptions per week for a drug that doesn’t work for treating or preventing Covid-19. Above, I wrote that the government isn’t responding clearly enough to this misinformation: here’s what I mean by that.
Scientists and doctors are trained to speak very carefully and precisely to one another. So rather than saying “X is false” or “Y doesn’t work,” we say “we don’t have evidence that X is true,” or “the evidence doesn’t support the effectiveness of Y.” That’s all well and good when you’re speaking to another scientist, but the general public hears these statements as something more like “X might work but we are still looking at the evidence.”
Uh uh. Not a good way to talk to the public.
Now, there actually have been several studies of ivermectin as a treatment for Covid-19, and here’s where the story might get confusing–but I’m going to try to keep it really clear. Virtually all of the studies showed that ivermectin simply doesn’t work, but one study out of Egypt (by Elgazzar et al.) seemed to show that it worked quite well. That was really surprising, but the story collapsed pretty quickly: it turned out the data was falsified, and parts of the paper were plagiarised. About a month ago, the study–which was still an un-reviewed preprint, was retracted by the publisher, Research Square.
Making things more confusing, several meta-analyses have already been published that relied on the flawed Egyptian study, and some of those papers report that ivermectin is effective. But a meta-analysis doesn’t contain any original data; instead, it’s an analysis that combines the results from a bunch of other studies. Those positive findings from meta-analysis papers rely heavily on the falsified Egyptian study, and (it turns out) on another very flawed study. For a deeper dive into those, see this excellent breakdown by the epidemiologist (and journalist) Gideon Meyerowitz-Katz (@GidMK, aka HealthNerd), who posted a long Twitter thread detailing the reasons why these meta-analyses, and some of the studies they include, cannot be trusted.
So the scientific picture is already clear: multiple studies show that ivermectin does not work. But rather than saying that in simple, direct English, here’s what the CDC states in their August 26 Health Advisory:
“there are currently insufficient data to recommend ivermectin for treatment of COVID-19”
“Clinical trials and observational studies to evaluate the use of ivermectin to prevent and treat COVID-19 in humans have yielded insufficient evidence for the NIH COVID-19 Treatment Guidelines Panel to recommend its use”
“Be aware that currently, ivermectin has not been proven as a way to prevent or treat COVID-19.”
The FDA isn’t much better (except for that one tweet). In a consumer advisory with the title “Why You Should Not Use Ivermectin to Treat or Prevent COVID-19”, they write:
“The FDA 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.”
See what I mean? This is how you’d explain things to another scientist, but the general public needs much more direct language.
So I’m saying it here: ivermectin doesn’t work in any way for Covid-19. It doesn’t prevent infection, it doesn’t cure the disease, and it doesn’t reduce your risk of anything.
Or, as the FDA’s Twitter account so eloquently put it, “You are not a horse. You are not a cow. Seriously, y'all. Stop it.”