Detroit Mayor Mike Duggan and the Henry Ford Health System announced Thursday that the Detroit-based hospital system will lead the first large-scale U.S. study of the effects of using the drug hydroxychloroquine to prevent coronavirus among health care workers and first responders.

The study is to include 3,000 people to see whether treating them with the medicine can keep them from being sickened by the disease.

The idea, Duggan said, is to target those who are putting their lives on the line to help others amid the pandemic, and will test whether giving "our health care workers and our first responders hydroxychloroquine doses early on could prevent the disease. Or if they do get the disease, could it be milder symptoms? And there's only one way to do that scientifically, and that's with a blind study."

Hydroxychloroquine, which is used to treat malaria, lupus and rheumatoid arthritis, appears to work in a couple of ways to help patients with coronavirus, said Dr. Marcus Zervos, the division head for infectious disease at Henry Ford Health System, in a previous interview.

It both reduces the amount of virus in a person's body and it seems to affect the immune system's response to COVID-19, and may prevent some of the immune-related complications of the virus, he said.

As part of the trial, participants will "take eight pills a week for eight weeks," Duggan said. "Some will get a placebo. Some will get different doses. And in a matter of four to eight weeks, we will have a really good idea of whether this works.

"We're going to be fighting the coronavirus for months, at least, to come. We need to have tools to fight back."

The eight-week controlled trial will begin enrolling study participants by early next week, said Dr. William O'Neil, a Henry Ford interventional cardiologist who is the study's organizer. Patients who receive the drug will take 200 milligrams daily for eight weeks.

Dr. Adnan Munkarah, Henry Ford's executive vice president and chief clinical officer, said COVID-19 has hit the health care community and first responders hard.

"We are embarking on a study that is very highly needed. ... Our first responders and health care workers are really in harm's way," Munkarah said.

"We are seeing them being exposed day in day out. Many of them, some who you know, have tested positive. Some, unfortunately, are in the hospital because of this virus. And, accordingly, when the opportunity opened to us to look at research trials... my partners and colleagues ... jumped on that occasion because we want to save people who are exposed.

"We want to make sure that our health care workers and our first responders are protected while they are committed to take care of us."

Right now, there is no treatment for COVID-19 that's approved by the Food and Drug Administration, and there's no cure, but Zervos said Henry Ford already is using hydroxychloroquine off-label in patients who are hospitalized with coronavirus.

"There is data both from the early published studies as well as experience from our colleagues in China that have treated a number of patients to justify its use in the therapy of sicker patients that are hospitalized with coronavirus infection," Zervos said.

"The goal of therapy is to take patients that have shortness of breath, that have compromised respiratory status, that have pneumonia, and by treating them with hydroxychloroquine, prevent them from the complications of progression of infection, ending up in an intensive care unit, ending up on a on a ventilator.

"In patients that are sicker, the goals are also to get the patient off the ventilator earlier, and to be able to get them out of the hospital."

O'Neill said there is evidence that hydroxychloroquine might also have a preventive effect.

"As soon this virus hit China, there were reports and people were trying to figure out how to treat it," O'Neill said. "There was one interesting report that said that people that were taking this drug hydroxychloroquine or plaquenil, ... a common treatment for lupus. ... If they were on that drug, they didn't get infected. So that was like the ...first evidence."

A small non-randomized study in France also suggested the drug might help prevent disease, he said, as did another small randomized study in China.

"So, from the scientific side, it looks promising, but not definitive," O'Neill said. "And we really, really need to know the answer whether or not this drug works or not.

"It's been well-thought out and we will definitively prove whether or not this drug prevents health care workers, first responders, the people who are at highest risk for getting this disease from getting this disease."

Although many have expressed concern about using hydroxychloroquine to treat coronavirus, O'Neill said the trial will not affect the availability of the drug for patients with lupus or arthritis at the pharmacy.

Contact Free Press health reporter Kristen Jordan Shamus: 313-222-5997 or kshamus@freepress.com. Follow her on Twitter @kristenshamus.