At a White House coronavirus briefing Sunday, President Trump continued to push hydroxychloroquine against the advice of doctors and health experts who say its efficacy against the coronavirus is unproven and warn of dangerous side effects.
Mr. Trump suggested he was speaking on gut instinct, and acknowledged he had no expertise on the subject.
“But what do I know? I’m not a doctor,” Mr. Trump said, after recommending the anti-malaria drug’s use for coronavirus patients as well as medical personnel at high risk of infection.
Saying that the drug is “being tested now,” Mr. Trump said “there are some very strong, powerful signs” of its potential, although health experts say the data is limited and that more study of the drug’s effectiveness against the coronavirus is needed.
“If it does work, it would be a shame we did not do it early,” Mr. Trump said, noting again that the federal government has purchased and stockpiled 29 million doses of the drug. Mr. Trump added, “We are sending them to various labs, our military, we’re sending them to the hospitals.”
“What do you have to lose?” Mr. Trump asked, for the second day in a row.
When a reporter asked Dr. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, to weigh in on the question of using hydroxychloroquine, Mr. Trump stopped him from answering. As the reporter noted that Dr. Fauci was the president’s medical expert, Mr. Trump made it clear he did not want the doctor to answer.
“He’s answered the question 15 times,” the president said, stepping toward the lectern where Mr. Fauci was standing.
On Saturday, Dr. Fauci had privately challenged rising optimism about the drug’s efficacy during a meeting of the coronavirus task force in the White House’s Situation Room, according to two people familiar with the events. The argument was first reported by the website Axios.
Peter Navarro, the president’s trade adviser who is overseeing supply chain issues related to the coronavirus, plopped a sheaf of folders on the table and said he had seen several studies from various countries, as well as information culled from C.D.C. officials, showing the “clear” efficacy of chloroquines in treating the coronavirus.
Dr. Fauci pushed back, echoing remarks he has made in a series of interviews in the last week that rigorous study is still necessary. Mr. Navarro, an economist by training, shot back that the information he had collected was “science,” according to the people familiar with what took place.
Dr. Megan L. Ranney, an emergency physician at Brown University in Rhode Island and editor for the journal Annals of Emergency Medicine, said in an interview on Sunday night that she had never seen an elected official advertise a miracle cure the way Mr. Trump has done.
“There are side effects to hydroxychloroquine,” Dr. Ranney said. “It causes psychiatric symptoms, cardiac problems and a host of other bad side effects.”
Dr. Ranney said hydroxychloroquine could be effective for some patients, but there wasn’t nearly enough scientific evidence to support Mr. Trump’s claims.
“There may be a role for it for some people,” she said, “but to tell Americans ‘you don’t have anything to lose,’ that’s not true. People certainly have something to lose by taking it indiscriminately.”
Dr. Kenneth B. Klein, a consultant who works for drug companies to design and evaluate their clinical trials, said patients with heart troubles and other underlying conditions are more likely to be severely affected by the coronavirus, so they might also be at higher risk of dangerous side effects from hydroxychloroquine.
“What have we got to lose?” Dr. Klein said, echoing similar remarks Mr. Trump has made in support of the drug. “We’ve got patients to lose from dangerous side effects.”
Other researchers have noted that while future trials may show a benefit, hydroxychloroquine has disappointed in the past, even though it has been tested as a treatment for other viruses, including influenza.
“Hydroxychloroquine has been studied as a possible antiviral therapy for many decades,” said Dr. Luciana Borio, who oversaw public health preparedness for the National Security Council in Mr. Trump’s White House and was previously the acting chief scientist at the Food and Drug Administration under President Barack Obama. “Despite showing evidence of activity against several viruses in the laboratory, it never showed success in randomized clinical trials.”
Mr. Trump defended his constant promotion of the drug, which is also often prescribed for patients with lupus.
“We don’t have time to go and say, ‘Gee, let’s take a couple of years to test it out,’ and test with the test tubes and the laboratories,” Mr. Trump said. “I’d love to be able to do that, but we have people dying today.”
“I’m not acting as a doctor. I’m saying, do what you want,” he added.
Two weeks ago, the American Medical Association discouraged the off-label use of hydroxychloroquine, chloroquine and azithromycin to treat Covid-19 and the stockpiling of those medications. Mr. Trump has promoted all three medications.