Across the world, scientists are searching for ways to fight COVID-19. What might prevent people from catching the coronavirus that causes the disease? And in people who are infected, what treatments might reduce symptoms or slow COVID-19’s spread?
After early studies showed promise, the FDA issued an emergency ruling that would allow doctors to use chloroquine and hydroxychloroquine (a less-toxic derivative of chloroquine) in people who were in the hospital with COVID-19. But the agency later revoked the ruling amid serious concerns about the drugs’ safety and how well they worked against the virus.
What Is It?
Chloroquine is a low-cost drug that has been in use for decades. First discovered 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?
Doctors thought chloroquine might reduce how long people with mild-to-moderate COVID-19 symptoms feel sick. They also hoped it would shorten the time when infected people are contagious.
What Does the Science Say?
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 infections 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.
Researchers around the world studied hydroxychloroquine’s effects in people with COVID-19. Some found early evidence of an effect against the new coronavirus. But many of those trials were stopped when they failed to show results or found serious 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.