Ivermectin is an old medicine used to treat parasitic infections in humans, for everything from river blindness to scabies. It is better known, perhaps, as a deworming medication that farmers and pet owners use to treat everything from cattle to dogs. The medicine has been used around the globe for 40 years. With the onset of COVID-19 -as people were desperate for some treatment, they have seized on different medications as a possible cure-all. The first was hydroxychloroquine, a medication commonly used to treat malaria. I first heard about this medicine from a neighbor, who told me that her spouse was obsessed with it. This was in the spring of 2020, when people in Boston and Cambridge were watching a tent being set up outside of of Massachusetts General Hospital to treat COVID-19 patients. People were desperate for a treatment. After being trumpeted by the Presidents of the United States and Brazil, a series of well-designed scientific studies showed that the medicine had no clear advantages while holding significant risks. As it fell out favor, people then turned to Ivermectin.
Of course, Ivermectin has been shown to have some antiviral properties. But so have many other medications. The question was- what was the evidence that it was useful against COVID-19? Very quickly my timeline on Twitter was filled with people talking about Ivermectin. The most common comment was perhaps that big pharmaceutical companies were hiding their knowledge about Ivermectin because it was off-patent and cheap. Dr. John Campbell -who has an excellent YouTube channel with daily updates on the COVID-19 pandemic- began to highlight Ivermectin as a potential treatment. An Indian state encouraged its use. Desperate people began to go to farmer’s Co-ops to obtain medicine intended for cattle for their use. Countries put Ivermectin into their national guidelines for the treatment of COVID-19, especially in hard-hit Latin America. People with Long COVID reported remarkable recoveries after taking the medicine. But what is the evidence for Ivermectin?
I have a friend who wrote a book about the use of mice in medical research, and the critical role that they play. But there is an old saying in medicine that mice lie and monkeys exaggerate. A lot of the early research in support of Ivermectin relied on studies on cells in the lab, which is even more distant from clinical practice. One Egyptian study that supported the use Ivermectin was withdrawn, and other studies were too small to draw a conclusion.
There has been a paucity of well designed studies to put the question to the test, until the Journal of the American Medical Association (JAMA) published a small study in which patients with mild COVID-19 were randomly assigned to receive Ivermectin or a placebo. As Emily Anthes reported in the New York Times there was no statistically significant difference in outcomes in the two groups. Although the patients with Ivermectin seemed to improve a couple of days more quickly, it didn’t meet the statistical bar to be a meaningful finding.
As the authors of the article also noted, this study didn’t provide any answers about whether the drug can prevent hospitalization or death. It will take a larger study to solve that question. As the NYT article also reports, Ivermectin has also become a polarizing question in the scientific community. Of course, it would be wonderful if Ivermectin proved to be a cheap, effective treatment for COVID-19. But the Mississippi Poison Control center has issued a public request that people stop taking Ivermectin. It turns out that people are buying medicine intended to deworm horses, taking it themselves, and then calling poison control after they have strange rashes or horrible nausea.
I can’t know what further studies will ultimately determine about Ivermectin. But I think that the level of hype about the medication is out of all measure with the evidence for its use at this time. About fifteen years ago I wrote a history of HIV/AIDS in Latin America, and I spent a lot of time talking with people throughout Latin America about the virus. It’s perhaps hard now for people who weren’t in those communities then to remember the fear, stigma and isolation that HIV could bring. Of course, that pandemic also brought with it a desperate search for any medication that might treat HIV. Those treatments ultimately came. But in the eighties and nineties there were many people who were traveled to Mexico or France for off-schedule and experimental treatments, which ultimately gave little benefit. In too many cases these medicines made sick people even sicker. But desperate people -who feel abandoned by the government and infuriated by the pharmaceutical companies- will search for these medicines.
Ever since my work with HIV/AIDS I’ve been interested in the conspiracy theories around epidemics. Much of the narrative about Ivermectin on social media -the pharmaceutical companies are concealing the truth, government agencies have been captured by big pharma, mainstream media is hiding the story because fear draws readers, only a small group of brave doctors are fighting to overcome a corrupt cabal- reads as a conspiracy theory to me. And it sounds like so many conversations that I had nearly twenty years ago in Latin America, when people told me that big pharma had a treatment for HIV, but was concealing it to make money. How is that many people are mistrustful of vaccines, but are so ready to take a drug before scientific studies support doing so?
If Ivermectin is a powerful therapeutic against COVID-19 we’ll eventually know, hopefully in time to use it as a key tool. It would be an inexpensive medication, with a long record of use in humans around the world. We need a large scale, double blind, study with Ivermectin as soon as possible. These trials are being done. But we don’t have that evidence now.
Until we have that data, the best that we can do now is use a layered approach to fight the disease: get vaccinated, take a booster when one is required, mask up with good quality masks indoors, and limit your exposure to others. While none of this is new, it’s hard advice to give when people are exhausted. The emergence of Delta has disappointed everyone, and people on the raft are beginning to think that they’re just going to fall into the water eventually. But all pandemics subside in time. And even if -as now seems increasingly likely- COVID-19 may always be with us, we will likely be in a much better place in six months. I’m not a scientist or a doctor, but rather a social scientist interested in public policy and pandemics in a historical context. But I’m confident that it’s better to take professional medical advice rather than searching the Dark Web for human dosage Ivermectin, or driving out to the Farmer’s Co-op to buy horse-feed flavored paste in a tube. You can see the FDA’s statement on why you shouldn’t take Ivermectin here.