Chloroquine is one option being explored. Recently, President Trump directed the FDA to not only search for new medicines but also study drugs that are already available. He’s expressed particular interest in chloroquine and hydroxychloroquine (a less-toxic derivative of chloroquine).

What Is It?

Chloroquine is a low-cost drug that has been in use for decades. First discovered in in 1934, it is the synthetic version of quinine, an antimalarial drug derived from the bark of the cinchona tree. Chloroquine is taken as a pill that you swallow. It’s already approved by the FDA to treat malaria as well as lupus and rheumatoid arthritis.

How Could It Help COVID-19 Patients?

The hope is that chloroquine might reduce how long people with mild-to-moderate COVID-19 symptoms feel sick. It might also shorten the time when infected people are contagious.

What Does the Science Say?

Chinese researchers recently showed that chloroquine can, at least in the lab, fight SARS-CoV-2, the virus that causes COVID-19, as well as other coronaviruses. But those are very early findings, and lab test results don’t always work out in people.

As far back as the late 1960s, scientists have known that chloroquine could kill viruses in a petri dish. Chloroquine is also commonly taken to prevent and treat malaria infection in areas where the disease is widespread.

But what about people who have viruses other than malaria? That’s less clear. Human studies in influenza and dengue have shown no effect, either good or bad. And in chikungunya, though chloroquine did well in lab tests, later research showed it might make the illness worse.

Recently, French researchers reported encouraging but early results on YouTube. They reported that in their study, hydroxychloroquine treatment appeared to reduce viral load, the amount of SARS-CoV-2 in the body. But that study was small (24 people) and wasn’t “randomized,” as are studies in which people are randomly assigned to get a particular treatment or placebo.

China is a hotspot for chloroquine research, with a few dozen trials underway in people.

The World Health Organization has said that it’s unknown whether chloroquine will be helpful against COVID-19. Still, the group is testing the drug’s potential as part of its Solidarity trial, a global effort to take place in eight countries.

In the U.S., several trials of hydroxychloroquine to treat the new coronavirus or help prevent health care workers from getting sick are being planned or will soon start enrolling patients, according to the CDC.

Side Effects

Chloroquine can upset your stomach, so people take it with food. Other side effects include headache, poor appetite, diarrhea, stomach pain, skin rash or itching, hair loss, and mood changes. Most of these problems are mild and temporary.

More serious side effects include eye problems (light flashes or streaks, blurred vision, difficulty reading), ear problems (ringing, trouble hearing), muscle weakness, drowsiness, vomiting, convulsions (sudden, unusual movement), irregular heartbeat, and breathing problems.

Be aware: If you take too much chloroquine, it can cause heart problems that can be life-threatening. It can also suppress the immune system. So only take this medicine under a doctor’s supervision.

Source: WebMD Medical Reference Reviewed by Arefa Cassoobhoy, MD, MPH on March 24, 2020