Tracey and his colleagues got the idea to study famotidine after it was observed that some patients in China taking the drug fared better than patients not taking the drug.

He said studies on the Chinese patients have not yet been published, but that Dr. Michael Callahan, an infectious disease specialist at Massachusetts General Hospital who worked with coronavirus patients in China, observed that some people with lower incomes were surviving longer than their wealthier counterparts who also had heartburn.

When Callahan and the Chinese doctors looked closer, they found that many of the people with lower incomes were taking famotidine, whereas the wealthier patients tended to take a different, more expensive drug.

“The poor peasants really seemed to do well on famotidine,” Tracey said. “There are a lot of anecdotes passing around that give us some hope.”