Vet professor warns against ivermectin as COVID drug

“I have a PhD in pharmacology and I’m not ever going to consider using a product for one species on another. Even with all my knowledge I can’t predict what’s going to happen.” - Chris Clark, Western College of Veterinary Medicine | File photo

Western College of Veterinary Medicine’s associate dean says risk of an overdose is high when using livestock medication

Animal doses of ivermectin should not be used to treat or ward off COVID-19, says University of Saskatchewan animal science professor Chris Clark.

Clark, who is also associate dean of the Western College of Veterinary Medicine, said that advice is backed up by a recent literature review by the Cochrane Library, a group of physicians from around the world who review multiple publications and try to find consensus.

“They could only find 14 studies that had any value,” he said.

The review concluded: “Based on the current very low- to low-certainty evidence, we are uncertain about the efficacy and safety of ivermectin used to treat or prevent COVID-19. The completed studies are small and few are considered high quality… Overall, the reliable evidence available does not support the use of ivermectin for treatment or prevention of COVID-19 outside of well-designed randomized trials.”

One published study has been retracted.

Neither Health Canada nor the Food and Drug Administration in the United States has approved ivermectin’s use for COVID treatment or prevention.

The FDA recently tweeted: “You are not a horse. You are not a cow. Seriously y’all. Stop it.”

Clark said ivermectin is used in livestock to treat intestinal round worms and parasites.

In humans, it is used to treat parasites and some skin conditions.

Early on in the pandemic there were some trials using it as a COVID treatment. Clark describes them as “very bad trials.”

People who take the animal version of the drug do so at great risk. The chance of overdose is extremely high since the doses were developed for animals weighing 500 kilograms or more.

Even among species formulations differ. There are equine and bovine types. And for cattle, there are oral, injectable and pour-on formulations.

“I have a PhD in pharmacology and I’m not ever going to consider using a product for one species on another. Even with all my knowledge I can’t predict what’s going to happen,” Clark said.

He said he understands that people are frustrated about COVID and want a solution but this isn’t it.

The Cochrane Library review noted 31 studies are ongoing and more information may come to light.

For now, Clark said people should listen to their doctors and read the labels. Veterinary drugs will say not for human use and do not say ivermectin can be used for corona viruses.

“You need to read the label and trust it more than what you see on Facebook or Twitter,” he said.

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