Editor’s note: On June 4, 2020, three of the authors on a May 22 Lancet paper cited in this story retracted their paper. The study found that taking hydroxychloroquine or chloroquine for COVID-19 raised the risk of death. Reports that the study might be based on faulty data provided by a company founded by coauthor Sapan Desai prompted the editors of the Lancet to issue an expression of concern about the study on June 3. Citing confidentiality, that company, Chicago-based Surgisphere Corp., declined to provide the data for an independent review, according to the retraction notice. “Based on this development, we can no longer vouch for the veracity of the primary data sources,” the other authors write.
President Donald Trump’s announcement that he is taking the drug hydroxychloroquine as a precaution against the coronavirus has once again thrown a decades-old antimalarial drug into the headlines.
There’s currently not enough data to say
whether the drug can protect people from catching COVID-19 or from getting very
ill if they do get infected with the virus. Studies of its use in treating very
sick patients have shown mixed results and, in some cases, have led to
dangerous side effects.
But now, with the president touting hydroxychloroquine
even as scientists issue cautions about its use, the drug has found itself at
the center of political divides, to the possible detriment of figuring out
whether it works.
Nevertheless, researchers are busy
testing hydroxychloroquine and a related drug called chloroquine to see if they
can either prevent infection or keep illness from worsening. Nearly 200
clinical trials are under way or planned around the world to test the drugs,
either alone or in combination with other medications. That includes at least
28 trials examining whether either drug can protect healthcare workers and
others at high risk of getting COVID-19.
Here’s what scientists know about the drugs
and their potential.
Why do researchers think chloroquine or hydroxychloroquine may prevent coronavirus infections?
Both are antimalarial drugs that also have
well-known antiviral activity against many viruses, including SARS and MERS. At
least they work against those viruses in lab dishes.
In lab tests, hydroxychloroquine can
SARS-CoV-2, the coronavirus that causes COVID-19, from infecting cells and
decreases replication of viruses that do get inside cells, researchers report
March 18 in Cell Reports. A February
4 report in Cell Research found that chloroquine also
inhibits the virus.