Hydroxychloroquine: Some Answers

By Shlomo Maital


What is the truth about hydroxychloroquine, the drug that is alleged to be helpful in treating coronavirus? This piece from the New York Times may be helpful.

What is hydroxychloroquine?

   Hydroxychloroquine is a prescription medicine that was approved decades ago to treat malaria. It is also used to treat autoimmune diseases like rheumatoid arthritis and lupus. It is sometimes referred to by its brand name, Plaquenil, and is closely related to chloroquine, which is also used to treat malaria.

Why has hydroxychloroquine even been considered as a possible treatment for the coronavirus?

There are several reasons. A promising laboratory study, with cultured cells, found that chloroquine could block the coronavirus from invading cells, which it must do to replicate and cause illness. However, drugs that conquer viruses in test tubes or petri dishes do not always work in the human body, and studies of hydroxychloroquine have found that it failed to prevent or treat influenza and other viral illnesses.

   Reports from doctors in China and France have said that hydroxychloroquine, sometimes combined with the antibiotic azithromycin, seemed to help patients. But those studies were small and did not use proper control groups — patients carefully selected to match those in the experimental group but who are not given the drug being tested. Research involving few patients and no controls cannot determine whether a drug works. And the French study has since been discredited: The scientific group that oversees the journal where it was published said the study did not meet its standards.

   A recent study from China did include a control group, and suggested that hydroxychloroquine might help patients with mild cases of Covid-19, the disease caused by the coronavirus. But that study had limitations: It was also small, with a total of only 62 patients, and they were given various other drugs as well as hydroxychloroquine. The doctors evaluating the results knew which patients were being treated, and that information could have influenced their judgment. Even if the findings hold up, they will apply only to people who are mildly ill. And the researchers themselves said more studies were needed.

Can hydroxychloroquine protect you from catching the virus?

   There is no evidence that hydroxychloroquine can prevent coronavirus infection. However, researchers at the University of Minnesota are testing the drug in people who live with coronavirus patients to see whether it can protect them

Is hydroxychloroquine approved by the Food and Drug Administration?

Yes, but for malaria, lupus and rheumatoid arthritis, not for Covid-19. For decades, doctors have been legally allowed to prescribe it for any condition they think it might help, a practice called off-label use. However, because of hoarding and high demand for hydroxychloroquine, some states like New York have ordered pharmacists to fill prescriptions only for F.D.A.-approved uses of the drug or for people participating in clinical trials.

Is hydroxychloroquine being given to coronavirus patients now?

Yes. Many hospitals are giving it to patients because there is no proven treatment, and they hope it will help. Clinical trials with control groups have begun across the world. A nationwide trial began on April 2 in the United States; it is to enroll 510 patients at 44 medical centers.   Researchers say those studies are essential to find out whether the drug works against the coronavirus. If it does not, time and money can be redirected to other potential treatments.

Is there any danger in taking hydroxychloroquine?

Like every drug, it can have side effects. It is not safe for people who have abnormalities in their heart rhythms, eye problems involving the retina, or liver or kidney disease. Other possible side effects include nausea, diarrhea, mood changes and skin rashes.

The leaders of three professional societies in cardiology warned on April 8 in the journal Circulation that hydroxychloroquine and azithromycin can each cause dangerous disruptions in heart rhythm, and they wrote, “There are very limited data evaluating the safety of combination therapy.”

If I can get hydroxychloroquine, should I take it to prevent coronavirus infection?

No, especially not without consulting a doctor who knows your medical history and what other medications you are taking. There is no proof that it works. And if it is being sold on the street or via the internet, it may be fake or unsafe.

An Arizona man in his 60s died last month after swallowing an aquarium cleaning product that had chloroquine on its label. He and his wife, who also became critically ill, had thought the product would protect them from the virus.

At this point, the best way to avoid infection is to practice the social-distancing and quarantine measures recommended by public health authorities. The Centers for Disease Control and Prevention also recommends that people wear cloth masks in public and wash their hands regularly.