What is hydroxychloroquine? Is it effective in treating coronavirus?

Before being diagnosed with COVID-19, President Donald Trump was an advocate for a drug that could be used to treat the coronavirus, but some experts raise concerns about limited, anecdotal evidence. Hydroxychloroquine is not new and has been used to treat ailments such as malaria and rheumatic diseases. Its anti-viral properties have also showed results in cases of influenza and SARS.

The drug has been discussed as a treatment for COVID-19 since the spring, and since Trump and many others supported use of the drug to help with the coronavirus, the discussion of the drug has resurfaced on social media. His doctor, Sean P. Conley, has said Trump received an infusion of an experimental antibody treatment developed by drug maker Regeneron and was also taking zinc, vitamin D, melatonin, aspirin and a generic version of the heartburn treatment Pepcid.

Conley has also said the president has begun a five-day course of remdesivir, an antiviral drug given emergency use authorization from the FDA to treat hospitalized COVID-19 patients. And, on Sunday, Conley said Trump had been given the steroid dexamethasone, which has been shown to help patients who are severely ill with COVID-19, but it can be harmful for patients with mild or moderate cases of the disease.

Hydroxychloroquine was not mentioned as a part of his treatment, but discussion has stirred since the announcement of the president’s diagnosis about it.

Many made note of the fact the drug Trump advocated for was not used in his treatment.

Some of Trump’s closest colleagues were still touting the drug as the president and several others who made contact with him in the last week announced their coronavirus diagnosis.

Here is everything you need to know about hydroxychloroquine and its role in the battle against COVID-19.

What kind of drug is it?

MedlinePlus classifies hydroxychloroquine as an antimalarial, prescribed to treat malaria. It has also been used to treat lupus and arthritis.

It first became approved for use in the U.S. in 1955, according to the New York Post.

You may have heard it by its brand name, Plaquenil. A similar drug, chloroquine, also exists and has been interchangeably used to treat COVID-19-related pneumonia.

Patients take hydroxychloroquine in the form of tablets, taken by mouth.

It would be considered an economical solution. Reports have called the drug's cost "negligible," making it worth investigation for treatment and prevention.

»COMPLETE COVERAGE: CORONAVIRUS

According to Christian Perronne, head of infectious diseases at a hospital in Paris, the drug has been around for “decades.”

Has it been tested?

Hydroxychloroquine was first tested in a laboratory setting for use against COVID-19 by Chinese Academy of Science researchers, who published their findings March 9. They found the drug to effectively kill the deadly virus.

On March 17, French researchers released results from a preliminary trial using 36 COVID-19 patients. The study, headed by Didier Raoult from Aix-Marseille University in France, has not yet been peer-reviewed but shows promising results.

Twenty of the patients received 600 milligrams of hydroxychloroquine daily, and the remainder did not to act as a control group.

After six days, 70% of the patients who received the drug were considered cured, compared with only 12.5% of the control group, according to Newsweek.

The Associated Press reported the head of the journal that published it has put out an "expression of concern" about the study's method.

Larger studies are underway, but results are not yet known.

»RELATED: Increase in deaths, confirmed cases show virus' toll is worsening

What’s the risk?

The drug has many potential side effects, and scientists want to study its effects in fighting COVID-19 in a controlled, carefully monitored setting.

According to Medline and The Associated Press, the drug can have numerous adverse effects on patients, including headaches, indigestion, dizziness, heart rhythm problems, severely low blood pressure and muscle or nerve damage.

The American Medical Association’s president, Dr. Patrice Harris, said she would not recommend hydroxychloroquine to a coronavirus patient, pointing to the high risk of heart problems.

“People have their health to lose,” she said. “Your heart could stop.”

Has it been approved by the FDA?

Not yet as a treatment to treat COVID-19.

Trump said in a news conference in March that "We're going to be able to make that drug available immediately" by prescription.

He described hydroxychloroquine as “fast-tracked” by the FDA.

More recently, trade adviser Peter Navarro advocated for the drug during a task force meeting April 6, directly challenging Dr. Anthony Fauci’s concerns.

»MORE: White House pushes unproven drug for virus, but doctors wary

The FDA says it hasn't been approved yet, according to Bloomberg.

FDA Commissioner Stephen Hahn said the U.S. will use hydroxychloroquine first in a clinical, controlled trial.

Experts still hold out hope that this old, inexpensive drug could be the answer to the coronavirus pandemic affecting hundreds of thousands globally.

»Click here to get the new AJC Mobile App