But he was worried that overhyping and overprescribing the drug so early might create a chloroquine-resistant coronavirus strain later — even though scientists have seen no evidence the novel coronavirus is mutating to become more dangerous. And he suggested on Twitter that the WHO and the Centers for Disease Control and Prevention should first review the drug.

In response to Bye’s concern, Rigano said a crisis trumped the necessity for scientific review. “world is burning,” he wrote on Twitter. “need all options on deck.”

“There are multiple reports published on pubmed at this point from chinese government,” Rigano also tweeted, referencing the government-run search engine that indexes medical papers around the world. “we are witnessing mass inefficiency by the ‘pros’.”

The paper was published on Google Docs the next day, with Todaro now listed as a coauthor, and including claims that Stanford University, the University of Alabama and the National Academy of Sciences were affiliated with the study.

They weren’t.

All three institutions, as well as Thomas Broker, a third researcher listed as a coauthor, subsequently said they were not involved in the paper and had no knowledge of its existence before it was published. Stanford also knocked down Rigano’s claim that he was an “adviser” to their medical school.

Still, the early association of these institutions gave the paper the prestige it needed to go mainstream, landing Rigano and Todaro on entrepreneur Elon Musk’s Twitter feed, then on Fox News.

In just a few days, hydroxychloroquine had morphed from one of several options that could be studied for preventing or treating Covid-19 into a potential superstar drug that some hoped could end the pandemic quickly. Todaro gained 10,000 Twitter followers; Rigano accumulated over 20,000 new followers. On Carlson’s show, Rigano called the drug “the second cure to a virus of all time.”

At the White House the next day, Trump announced the FDA had approved the “promising” drug for immediate use — a pronouncement that Dr. Anthony Fauci, the government’s top infectious disease expert, had to walk back, clarifying that it had been approved only for clinical trials.

As of now, there is no conclusive scientific evidence that hydroxychloroquine is effective in treating coronavirus patients.

Most scientists who study these issues warn that while the drug may have shown some early promise, the data has been thin — and that results are mixed. A small early study out of France suggested benefits, but experts have since questioned that research , saying the lead researcher has a dubious history with manipulating data and noting that the researcher chose who would get the drug, skewing the results. On Monday, the scientific society that published the French paper formally said it now believes the research did not meet “the expected standard” about why or how patients were selected.

More recently, a Chinese study suggested no effect from the pills.