President Trump claims a drug used against malaria has been approved in the United States to treat the new coronavirus.
Chloroquine is one of the oldest and best-known anti-malarial drugs.
So is the president right and what is known about its effectiveness?
Chloroquine has been around for decades. It’s no longer recommended in much of Africa because of the resistance built up to it by the malaria parasites.
Some countries have introduced regulations to curb the use of the drug, but it has remained popular in those with an active private-sector drug market and is sold widely.
Image copyright Reuters Image caption American scientists have begun a trial to see if chloroquine will help treat coronavirus
What is the status of global research?
It’s no surprise that chloroquine has been part of the search to help coronavirus patients.
It’s well-known, and cheap and easy to produce. In treating malaria patients, the drug has been used to reduce fever and inflammation.
“Chloroquine seems to block the coronavirus in lab studies. There’s some anecdotal evidence from doctors saying it has appeared to help,” says James Gallagher, BBC health correspondent.
But crucially there have been no complete clinical trials which are important to show how the drug behaves in actual patients, although they are under way in China, the US, UK and Spain.
The World Health Organization says that so far there is no definitive evidence of its effectiveness, but it is part of the continuing trials.
“In order to know which therapies could work to treat the viral infection we need to undertake clinical trials to gain the full evidence to know whether they work or not,” says Prof Trudie Lang, director of The Global Health Network at Oxford University.
Interest in the drug had already been gaining traction online.
Searches for chloroquine have spiked in the past week, according to Google Trends data, and entrepreneur Elon Musk caused a stir when he tweeted out some research into it.
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