A common medication in dermatology may help against COVID-19

April 25, 2020 / Duncan Fisher
Ivermectin, an old anti-parasitic, slows coronavirus replication

If you’ve got a dog, you’ll know about ivermectin. It’s a drug that vets use to control heartworm infestations. It’s a semi-synthetic compound that disables parasites by messing up the normal flow of ions across their cell membranes. Ivermectin has been around since the 1970’s, and is in wide use in animal populations these days.

It’s used in humans, too, who also get parasites. In developing countries ivermectin has been of tremendous help against river blindness and elephantiasis, both of them parasitic diseases. Less dramatically, your own dermatologist sometimes reaches for it to control scabies rash. Scabies is a skin infestation of tiny Sarcoptes mites. It works very well, doesn’t tend to cause problems, is easy to take (it’s a tablet), and it doesn’t cost much.

The thing about ivermectin is that it has another trick: it has anti-viral activity, across a surprisingly wide range, that includes monsters like HIV-1 and the dengue and West Nile viruses.

The exact way that ivermectin works, at the molecular level, and one or two things that are known about the COVID-19 virus (actually called SARS-CoV-2), made a team of immunologists in Australia wonder recently about the drug’s possible use in the coronavirus pandemic we’re in. They did some testing, on cells in the laboratory, and got some gratifying results.1

Ivermectin did seem to slow viral replication as they expected, and probably through the very mechanism they imagined (inhibition of IMPα/β1-mediated nuclear protein import, if you’re following these things).

Granted, these were cells in a dish, but it was proof of concept. The team believes that further work, ultimately in humans, is warranted. If it goes the way they hope, there could emerge a drug, taken orally, early in the infection, that would limit the viral load, and make the infection much less transmissible. The drug itself, following ivermectin’s gentle safety profile, ought to be easy on patients, too.

It’s early days yet. Drug development is not straightforward. It may or may not work. But on the face of it, this is encouraging news.

1 Caly, L, et al. Antiviral Research 178, June 2020, 104787; e-pub ahead of print: https://doi.org/10.1016/j.antiviral.2020.104787

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