Japanese firm says ivermectin shows ‘antiviral effect’ against Covid-19

The controversial drug ivermectin shows an “antiviral effect” against Covid-19, a Japanese drug company said on Monday.

The controversial drug ivermectin showed an “antiviral effect” against Omicron and other coronavirus variants in joint non-clinical research, a Japanese drug company said on Monday.

Trading and pharmaceutical company Kowa Co Ltd, which has been working with Tokyo’s Kitasato University testing the drug as potential treatment for Covid-19, did not provide further details, Reuters reported.

Ivermectin has been popularised as a Covid-19 treatment by some doctors and the likes of podcast host Joe Rogan, even as health authorities and the drug’s manufacturer Merck warn against its use, citing lack of evidence that it works against the virus.

A clinical trial being run in the UK by Oxford University, announced in June 2021, is ongoing.

The Oxford researchers told Reuters on Monday that they did not want to comment until they have results to report.

Ivermectin first began to be touted as a therapeutic for Covid-19 in early 2020 after scientists in Melbourne found it could inhibit SARS-CoV-2 in the lab in high doses.

“It was enthusiastically adopted by some clinicians and healthcare systems before any significant human trials were conducted, and subsequent trials have been largely small and conflicted,” Associate Professor Justin Denholm, principal investigator on the Australasian Covid-19 Trial (ASCOT), wrote in August 2021.

“Now, a number of retrospective reviews and meta-analyses have been released, which mostly agree that studies to date have generally been of low quality and high risk of bias, but offering different conclusions about whether ivermectin improves outcomes.”

In September, Australia’s Therapeutic Goods Administration (TGA) banned doctors from prescribing ivermectin off-label.

General practitioners are now only able to prescribe ivermectin for TGA-approved conditions, such as scabies and certain parasitic infections.

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“These changes have been introduced because of concerns with the prescribing of oral ivermectin for the claimed prevention or treatment of Covid-19,” the TGA said at the time.

“Ivermectin is not approved for use in Covid-19 in Australia or in other developed countries, and its use by the general public for Covid-19 is currently strongly discouraged by the National Covid Clinical Evidence Taskforce, the World Health Organisation and the US Food and Drug Administration.”

Ivermectin was first discovered in 1975 and came into medical use in 1981. It was approved for human use in 1988.

In 2015, half of that year’s Nobel Prize in Physiology or Medicine was awarded jointly to ivermectin’s discoverers, Satoshi Ōmura of Kitasato University and William Campbell of Merck.

You are not a horse. You are not a cow. Seriously, y'all. Stop it. https://t.co/TWb75xYEY4

— U.S. FDA (@US_FDA) August 21, 2021

The medication is sold in both human and animal formulations.

Veterinarians use it to deworm domestic animals and cattle.

For humans, it exists in tablet form and has been widely used in Africa to treat intestinal strongyloidiasis and onchocerciasis – also known as river blindness – which are conditions caused by parasitic worms.

Topical formulations are also used to combat head lice and skin conditions such as rosacea.

When the medication is taken as intended it is low risk – however, when taken in large doses it can cause serious side effects including severe nausea and vomiting, and neurological effects such as dizziness, seizures and coma.

In August last year, the US FDA told Americans to stop taking the drug by referencing the veterinary version.

The FDA said it had seen a rise in reports of patients being hospitalised after self-medicating with ivermectin.

“You are not a horse. You are not a cow. Seriously, y’all. Stop it,” the FDA tweeted.