Ivermectin, the true facts.

In response to: You may have seen ads on television for Heartgard, which prevents heartworm disease in dogs, and treats and controls intestinal worms in animals. One of two active ingredients in Heartgard is ivermectin.

Ivermectin is a broad spectrum anti-parasitic, with approved uses in animals and humans. The drug was developed in the late 1970s. In veterinary medicine, it is indicated to prevent and treat heartworm. In humans, ivermectin is indicated for, among other conditions, two neglected tropical diseases, river blindness (onchocerciasis) and lymphatic filariasis.

Bizarrely, in right-wing political circles, ivermectin has become increasingly popular as an antidote to Covid-19. The drug is embroiled in a Covid-19 culture war that pits (as yet) unproven treatments against proven measures, such as vaccines. On Friday, August 27th, in a speech at the Texas Youth Summit, Representative Louie Gohmert touted ivermectin as an effective treatment for Covid-19, despite there being no substantiated scientific evidence to back this up.

Gohmert is not alone in spreading misinformation. Social media is rife with assertions that ivermectin is beneficial for preventing and treating Covid-19. As a result, in a number of states poison control centers are being inundated with calls from people who’ve taken ivermectin and are experiencing severe adverse effects. In response, the Food and Drug Administration has been urging people not to ingest ivermectin, with colorful tweets like this one: “You are not a horse. You are not a cow. Seriously, y’all. Stop it.”

Many talking heads have taken to the airwaves to decry what appears to be irrational behavior on the part of ivermectin enthusiasts. Rachel Maddow of MSNBC said: “Literally people won’t take the vaccine because they’re super suspicious of that, but they’re taking horse deworming medication that they’re buying at a feed store.”

The unfolding ivermectin culture war is reminiscent of last year’s polarizing debate on hydroxychloroquine. Hydroxychloroquine is another rather old drug, indicated for malaria. Like ivermectin, hydroxychloroquine is on the World Health Organization’s essential drug list. Essential medicines support the priority healthcare needs of patients, particularly in developing nations, and are selected based on their public health relevance, evidence of safety and efficacy, and comparative cost-effectiveness.

Of all drugs right-wingers would have gravitated to, ivermectin and hydroxychloroquine are most unusual candidates, in that they’re largely used in humans in developing nations for conditions rarely seen in the U.S.

All the talk of ivermectin being a deworming agent for animals doesn’t do justice to its crucial role in combating two devastating neglected tropical diseases in humans: River blindness and lymphatic filariasis. These diseases impose a significant burden on public health, especially in developing nations.

In 1987, the pharmaceutical company Merck established the Mectizan (ivermectin) donation program. This program is considered an exemplar among drug donation arrangements. Three hundred million people have been treated with ivermectin, donated by Merck in more than 30 countries.
So, ivermectin has proven human uses, but Covid-19 is not one of them. And, the company that manufactures ivermectin, Merck, has explicitly stated this. There are several ongoing clinical trials involving ivermectin as a possible treatment of Covid-19. But, at present there aren’t any validated data on ivermectin’s efficacy against Covid-19 in people.