@Rudderneck
It was originally developed for use in veterinary medicine; it is most widely used there; & WRT its usage & Covid-19, most of the issue is people quite literally purchasing horse wormer online & taking it, such that the FDA & other US government information providers warn against doing so. So rather than being in any way disingenuous it’s entirely accurate to say “horse wormer” because vanishingly few people are getting Ivermectin prescribed to them but are, as I said, purchasing & consuming the product intended for equines. And crucially, in the specific instance I was linking to, the man who died was taking the veterinary formulation of ivermectin.
Apparently Ivermectin’s drug class is actually antihelmintic so even narrower than just “antiparasitic”. 🤷♀️
In the UK it can be prescribed for: Papulopustular rosacea (explanation, no images); Chronic Strongyloides infection (aka threadworm, again, no images); Onchocerciasis (WHO information on River Blindness: no images on landing page, I’ve not read everything); & Scabies, in combination with topical drugs, for the treatment of hyperkeratotic (crusted or ‘Norwegian’) scabies that does not respond to topical treatment alone (NHS Inform - no images).
Only the first on the list is (again, in the UK) a licensed use; the others, ie oral usage, are unlicensed. Interestingly, that is also the one instance where it isn’t obviously acting as an antiparasitic/people might not appreciate it’s functioning as such; & it’s also the only topical usage. However, a 2016 paper in Clinical, Cosmetic and Investigational Dermatology posited that there is a multifactorial etiology of the disease. Topical ivermectin has emerged as a viable treatment option, which is likely to be beneficial due to its activity as an anti-inflammatory and anti-parasitic agent targeting Demodex mites which may be colonizing the pilosebaceous units of patients with the disease. The NICE Evidence Summary from January that year is on pretty much the same page: The mechanism of action for treating the inflammatory lesions of rosacea is not known, but may be linked to the anti‑inflammatory effects of ivermectin, as well as causing the death of Demodex folliculorum mites. Crucially, though, this 2022 paper in Dermatologic Therapy confirms that the mechanism is as had been suggested in 2016. (The 2017 paper that made the confirmation is not open access but is referenced.)
I didn’t say ivermectin isn’t a useful drug. But, as per the 2022 Cochrane Review (link in my previous post) it’s not useful at all in treating Covid. Its uses full stop are pretty narrow: & they are all antiparasitic; although the one topical treatment exploits its anti-inflammatory properties too.