The active ingredient in many heartburn medications is being studied as a coronavirus treatment, leading to shortages of popular heartburn brands at major US pharmacies.

Famotidine, an antacid and antihistamine found in the brand Pepcid AC and generic medications, is being used in a trial by researchers at Northwell Health in the New York City area, Kevin Tracey told Business Insider.

Even as Tracey urged people not to go out and hoard heartburn medicines, retailers like Amazon and Walgreens appeared to already be experiencing shortages.

On Amazon, Pepcid AC and all three generic options found through a search were unavailable or otherwise out of stock on Monday afternoon. The company did not immediately respond to a request for comment.

At CVS, the US's largest pharmacy chain, famotidine – either in Pepcid or generic form – was out of stock at most New York locations, according to its website.

Searches in Los Angeles, Chicago, Houston, and other cities produced similar results, with most locations out of stock. The company did not immediately respond to a request for comment.

Walgreens appeared to have experienced the same rush as CVS, with ZIP codes around the US showing out-of-stock notices at most locations searched by Business Insider, with a few stores showing limited stock. The company did not immediately respond to a request for comment.

It's still too early to tell if famotidine will be useful in any treatment for coronavirus patients, Tracey said. Even if some benefits are found, patients in the study are taking extremely high doses intravenously, far more than someone would ever take for heartburn.

"You should not go to the drugstore and take a bunch of heartburn medicine," he told CNN.

Science Magazine reported Sunday that the researchers had fought to keep the study quiet, fearing a run on the medicines.

"If we talked about this to the wrong people or too soon, the drug supply would be gone," Tracey told the publication.

There was already ample evidence to support his fears.

The situation surrounding the possible benefits – and subsequent shortages – of famotidine is not unlike what happened earlier this year with an antimalarial pill created in the 1940s that was hyped by influential leaders, including President Donald Trump and Tesla CEO Elon Musk.

Two weeks after Business Insider covered their hopes that the drug, hydroxychloroquine, could be used to fight the coronavirus and the resulting shortages as Americans stocked up, the US Food and Drug Administration officially recognised the shortages.

There remains no peer-reviewed clinical data showing that these old generic drugs, which some people still take for Lupus and other conditions, work against COVID-19.

"The fear, the chaos, and the panic is a far greater threat to humanity than a virus, especially for a therapy that may or may not work," Michael Rea, the CEO of Rx Savings Solutions who was previously a pharmacist, told Business Insider of the explosive demand for drugs rumoured to be a treatment.

Rea advises all healthcare workers to act professionally in these times, he said.

"Don't let fear dictate your decisions," Rea said.

"Only use the drug, prescribe the drug, obtain the drug if you truly need it."

This article was originally published by Business Insider.

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