Black market emerging for COVID-19 candidate ivermectin

Antiparasitic drug ivermectin is still being put through its paces in clinical trials as a possible therapy for COVID-19, but an illicit trade in the drug is already springing up.

There are reports of a black market trade in ivermectin emerging in South Africa and other countries which are struggling to get access to drugs that have been shown to work in COVID-19, such as Gilead Sciences’ antiviral Veklury (remdesivir).

Ivermectin is approved to treat various parasitic diseases in animals and for two parasitic worm infections in humans – intestinal strongyloidiasis and onchocerciasis – as well as being used in topical formulations for infestations like head lice.

It emerged as a possible COVID-19 treatment early on in the pandemic after researchers showed it could inhibit the SARS-CoV-2 virus in cell culture experiments. However, shortly after the FDA issued an alert warning against self-medication with the drug – which is available on prescription only – until it had been properly assessed in clinical trials.

There have been a couple of dozen small trials of the drug, and according to researchers at the University of Oxford in the UK these have generated promising results.

They are just about to start new study – called PRINCIPLE and backed by the UK government – to see if those preliminary results with ivermectin can be reproduced at a large scale, at the same time as testing another candidate called favipravir.

Both are low-cost, orally-administered, generally available generic drugs. And that means they could be an important treatment option for less developed areas of the world, which are likely to struggle to access high-tech vaccines, monoclonal antibodies, and novel therapeutics that starting to be used in high-income countries.

That data still needs to come in of course, and in the meantime the South Africa Health Products Authority (SAHPRA) has said there are widespread reports of use of veterinary ivermectin being used for prophylaxis or treatment of COVID-19 using the veterinary product.

Meanwhile, an article in South Africa’s Independent newspaper says that testimonials by health professionals, lobby groups and individuals are flooding social media, endorsing its use against COVID-19 and encouraging illegal purchasing and use.

According to SAHPRA, the quality of the individual trials carried out on ivermectin to date is low. It notes however that a meta-analysis of all the studies has concluded that use of the drug may lead to faster time to viral clearance, shorter hospital stays and higher rates of clinical recovery, as well as some improvement in survival rates.

“However, the meta-analysis also concluded that additional randomised clinical trial data were needed to confirm clinical benefit in COVID-19 infections as well as define an optimised dosing regimen,” it added.

In the meantime, a scramble for access to illicit ivermectin could raise the risk of people being exposed to side effects from the use of veterinary medicines and – almost inevitably – counterfeit medicines pushed into the supply chain quickly to satisfy the high demand.

Last year, Mexico’s authorities said they had already come across counterfeit batches of ivermectin being sold illegally to the public.

The FDA said last year that it was concerned about the health of consumers who may self-medicate by taking ivermectin products intended for animals, thinking they can be a substitute for ivermectin intended for humans.

“People should never take animal drugs, as the FDA has only evaluated their safety and effectiveness in the particular animal species for which they are labelled,” it said. “These animal drugs can cause serious harm in people.”