Chloroquine has been used to treat malaria for decades, and its more recent reformulation of hydroxychloroquine has often been prescribed for patients with lupus and arthritis. Because it was approved to treat malaria by the FDA in 1949, it can also readily be prescribed under the table by physicians for COVID-19.
President Trump, at his daily press briefing, claimed that chloroquine had been approved for use in treating the coronavirus by the US Food and Drugs Administration (FDA). However, the FDA has made it clear it has not been approved for treating those infected with the COVID-19.
There are, however, studies underway to see if chloroquine can be effective in the treatment of COVID-19. But, that does not make it clear to use against or medicate COVID-19.
How Are The Studies Looking?
There have been no complete clinical trials which show how the drug behaves in actual patients, although they are underway in China, the US, UK and Spain. However, in the lab - the drug seems to block out the virus.
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," Prof Trudie Lang, director of The Global Health Network at Oxford University told BBC news.
Searches for chloroquine have spiked in the past week, according to Google Trends data, and the internet has also been curious about its effects.
How Does Chloroquine Work?
Chloroquine, first developed in the 1940s, earned FDA approval as a malaria treatment in 1949 and stood as the go-to treatment for the disease. Scientists, after reviewing a 2005 report published in the journal Virology, which examined the related virus - SARS-CoV, suggested that chloroquine could prevent the spread of that virus, which caused severe acute respiratory syndrome 20 years ago.
Chloroquine interferes with the virus's ability to replicate in two ways. First, the drug enters compartments called the endosomes within the virus-cell. Endosomes tend to be slightly acidic, but the chemical structure of the drug boosts their pH, making the compartments more basic. Many viruses, including SARS-CoV, acidify endosomes in order to breach the cell membrane, release their genetic material and begin replication; chloroquine blocks this critical step.
The drug also prevents SARS-CoV from plugging into a receptor called angiotensin-converting enzyme 2. When the virus inserts its spike protein into the ACE2 receptor, it sets off a chemical process that alters the structure of the receptor and allows the virus to infect. An adequate dose of chloroquine appears to undermine this process.
So Could It Cure COVID-19?
In February, a research group led by virologist Manli Wang of the Chinese Academy of Sciences put the idea to the test and found that chloroquine successfully stopped the spread of SARS-CoV-2 in cultured human cells.
Preliminary reports from China, South Korea and France suggest that the treatment is at least somewhat effective in treating human patients, and some hospitals in the U.S. have begun administering the drug, according to The New York Times. In addition, the FDA is also organizing a large clinical trial to formally assess the drug's effects.
However, due to a short supply of chloroquine in China, and the fact that an overdose can lead to acute poisoning or death in humans, Wang's team also investigated the closely related drug hydroxychloroquine. Though it shares a similar structure, hydroxychloroquine shows lower toxicity in animals and remains widely available as a treatment for lupus and rheumatoid arthritis.
Assuming the drugs are well received in clinical trials and seem effective in treating COVID-19, the FDA will take measures to increase supply.
So, as of now taking the drug to medicate the virus is not advised as it can cause a lot more complications, if not death. Until the FDA, and WHO does not advise or approve the drug, taking chloroquine or any other drug for that matter is not recommended.