Thread by @BugQuestions

Why are people poisoning themselves with horse dewormer to treat COVID-19?

Let's explore ivermectin in this week's #DeepDive

Ivermectin is a medication which is perscribed to combat parasites.

It jams itself into chloride channels, permanently turning the nerves off.

It can't do that to people, so it has a pretty good safety profile if you stick to the correct doses.

Okay, but viruses don't have nerves.

So why would an insecticide work on a virus?

It does something else, too. It blocks the import of proteins into the nucleus.

Kind of.

dicyt.uto.edu.bo/observatorio/w…

See, once we get outside of a petri dish, the antiviral properties of ivermectin become a bit questionable.

Sometimes, it works in mice, sometimes it doesn't. Bodies are a lot more complicated than petri dishes.

XKCD
bit.ly/3zlEfju
go.nature.com/3kjQ9EB

The other problem, is that for the medicine to reach the levels needed to treat COVID-19, you need a really high dose.

Like, well over 10x what's currently given to people.

ascpt.onlinelibrary.wiley.com/doi/full/10.10…

So there's SOME evidence it works, at least. In animal models. And in cells.

The big paper which set all of this off was a well-performed paper looking at the drug in cell cultures.

sciencedirect.com/science/articl…

This paper set off a lot of clinical trials, many with varying quality, different confounding factors...it's just hard to parse so many trials run so differently on the fly.

I'm not a doctor, so I'm going to refer to BMJ here:

ebm.bmj.com/content/early/…

Ultimately, though, it looks like it has some weak effects. Weak, but positive.

So maybe if we find the right dosing regime.

The problem, however, is that a lot of this is based on preprints.

...and a lot of this data just isn't quality data.

One paper that's been widely cited in online spheres relied on a withdrawn paper for 15% of its effect size.

nature.com/articles/d4158…

So that's where we are on ivermectin. It's a big "maybe" with a lot of legitimate questions about whether it works...which it very likely might not based on how it's metabolized in people.

Vaccines DO work, so if you can, get vaccinated.