As the coronavirus pandemic rages on, some drugs are showing promise in treating patients with COVID-19, the disease caused by the novel coronavirus.

There are no approved treatments or vaccines for COVID-19, but researchers are testing a slew of existing drugs to see if they could work.

One of those drugs is called chloroquine, a widely used anti-malaria pill that was first approved in the US in 1949.

Countries including China, South Korea, and Belgium have added it to COVID-19 treatment guidelines as anecdotal reports have suggested that it might work.

There is no peer-reviewed clinical data showing that chloroquine works against COVID-19. But that hasn't stopped doctors from using it or US prescriptions from spiking. Even President Donald Trump and Tesla CEO Elon Musk have touted its potential.

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In the scramble to find drugs to treat COVID-19, the illness caused by the novel coronavirus, one drug has rapidly gained the public's attention, despite a little evidence showing it works.

The drug is chloroquine, an anti-malaria pill that was first approved in the US in 1949. A much more widely prescribed version called hydroxychloroquine is also being tested against the virus. Early laboratory research and anecdotal reports about using it for people with COVID-19 have shown encouraging signs that it may work to fight the virus.

As dozens of drug companies rush into research projects to develop antibodies and other next-generation therapeutics, chloroquine stands out as a potentially simple, cheap, and scalable treatment, though we haven't yet seen data from any randomized clinical trials, the gold standard of medical research.

"If clinical data confirm the biological results, the novel coronavirus-associated disease will have become one of the simplest and cheapest to treat and prevent among infectious respiratory diseases," a group of French researchers wrote in a paper published on February 15 in the International Journal of Antimicrobial Agents.

One of the three authors of that article was Didier Raoult, a prominent infectious-disease expert who ran a small clinical trial in France testing hydroxychloroquine in a few dozen COVID-19 patients. It's one of many clinical studies around the world testing chloroquine or hydroxychloroquine.

Early reports of Raoult's trial were positive, with Raoult saying chloroquine appeared to shorten the time that people with COVID-19 are infectious.

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When combined with the antibiotic azithromycin, it also reduced the viral load in these patients, he added. Azithromycin helps fight lung infections that can come with COVID-19 and may play a role in fighting the virus, Medscape reported.

This French study is one small, low-quality study that needs to be replicated on a larger scale. It tested a very small group with no long-term follow up data, and six patients dropped out early and were excluded from the main analysis. The French goverment is expanding this testing to see if the results hold up.

Adding to that skepticism, another tiny trial of 30 COVID-19 patients in China published on March 24 showed no difference between hydroxychloroquine and placebo.

While experts caution against anyone reaching conclusions about the drug's utility in COVID-19, President Donald Trump has repeatedly touted chloroquine by name as a promising potential treatment. On Thursday, US Food and Drug Administration Commissioner Stephen Hahn said chloroquine and hydroxycholoroquine will be made available to patients under a compassionate-use program as more data is collected.

Compassionate-use programs are generally for terminally ill patients who have no other treatment options. They allow doctors to give patients treatments that have not proven to be safe and effective.

Hydroxychloroquine isn't a benign drug either. It can cause severe side effects if not taken properly, including vision loss, low blood sugar, and heart problems. A 2018 review article also cautioned hydroxychloroquine can cause neurological side effects for some, with the frequency unknown of serious complications like psychosis and suicidal tendencies.

Self-medicating can be fatal. An Arizona man died after deciding to take a non-pharmaceutical version of chloroquine used to clean fish tanks.

Chloroquine is now a leading experimental treatment for COVID-19

Steven Seedhouse, a biotech analyst at Raymond James, said chloroquine was just as promising as any treatment option for COVID-19. That includes remdesivir, an antiviral drug being developed by the giant biotech company Gilead Sciences that World Health Organization officials have called "the most promising candidate" for COVID-19 treatment.

He recently analyzed the early evidence for three top drugs being tested for COVID-19 — remdesivir, chloroquine, and Kaletra, an HIV drug sold by AbbVie — and concluded that chloroquine was the most promising candidate.

"If we had to pick one of the three at this point that actually seems most likely to have the biggest impact on treating COVID-19 in the coming months/years, it would be chloroquine," he said.

Early reports about chloroquine's effectiveness have also caught the attention of Elon Musk. The Tesla CEO tweeted on Monday that it might be worth considering chloroquine for COVID-19, saying the drug saved his life when he faced a serious case of malaria.

Repurposed antiviral drugs aren't likely to be cure-alls, but they are the only near-term treatment options. It will take months, if not years, to determine whether a new drug or vaccine is safe and effective.

Vaccines in particular are seen as the gold standard for infectious diseases because they protect people from infections in the first place.

But if drugs like chloroquine and remdesivir work, they could bring major relief to healthcare systems around the world that are feeling the weight of a pandemic.

In the US, there are widespread concerns about the likelihood that hospitals will run out of beds and ventilators as the virus spreads, forcing doctors into difficult rationing decisions. That's already happening in Italy.

Remdesivir, given as a 10-day intravenous infusion, could shorten hospital stays and lower ventilator use if it can help patients with serious COVID-19 cases recover faster.

Chloroquine is being tested to treat COVID-19 and prevent people from catching it

As a simple pill, chloroquine could prevent some COVID-19 patients from worsening to the point of needing hospitalization. But there is no high-quality clinical data showing if it works to halt COVID-19.

Seedhouse said that even in the face of a pandemic, it is essential to stick to evidence-based approaches.

"All we have is some preclinical rationale and some mechanistic rationale, but no hard randomized clinical data yet," Seedhouse said. "I think it's appropriate to be cautious on chloroquine and anything else."

Bigger, higher quality trials are now gearing up, including an NYC-based trial planning to test 1,600 people who live with someone diagnosed with COVID-19. Those researchers are testing to see if hydroxychloroquine works in people at high risk of infection compared to a placebo treatment.

There's also randomized controlled trials in Mexico testing both 500 COVID-19 patients with severe respiratory disease as well as 400 healthcare workers as a prophylaxis treatment.

Researchers also plan to test chloroquine to see whether it can help prevent healthcare workers from getting the virus in the first place.

US prescriptions are spiking, straining the supply of the medicine

While peer-reviewed results are the standard in medicine, the lack of that data hasn't prevented the world from acting.

China has found that chloroquine is effective against COVID-19, the state-owned Xinhua news agency reported on February 17. Countries including China, South Korea, and Belgium have added chloroquine to their treatment guidelines.

US physicians don't appear to be waiting for data either. Prescriptions for chloroquine and hydroxychloroquine have skyrocketed, straining the supply chain.

Read more: Elon Musk and Trump are touting a 1940s malaria pill as a potential coronavirus treatment. But supplies are already running short as prescriptions spike.



Doctors in the US have broad authority to prescribe approved medications for so-called off-label uses, or conditions that the drug isn't approved to treat.

Early reports of success 'should be taken seriously'

Andrea Savarino is an Italian scientist who has worked at the Italian National Institute of Health, the country's top medical research body, since 2006. He has been studying chloroquine and its potential uses for even longer than that, starting as a virologist in 1994.

During the 2003 outbreak of SARS — also a coronavirus — Savarino showed in laboratory research that chloroquine may be a useful weapon against it. But by the time his research was published in The Lancet in November 2003, the outbreak had dissipated and there were no human cases available to test.

"There has been a number of press releases, unfortunately not yet papers, but even the local experiments are things that should be taken seriously," Savarino told Business Insider. "Chloroquine plus the HIV inhibitors has produced interesting results, at least curative results, both in China and Australia."

In Australia, researchers at the University of Queensland have said a combination of chloroquine and Kaletra led to the recovery of some of the first COVID-19 patients in Australia.

"It's a potentially effective treatment," David Paterson, the director of the university's Centre for Clinical Research, told the Australian news site News.com.au.

Savarino said he had heard anecdotal accounts from other countries as well, including Japan, India, and Thailand.

"Given these promising results, I am of course optimistic, but I cannot give percentages of success as of now," Savarino said. He emphasized the need to collect more data before reaching conclusions.

Savarino said he was developing an online platform to collect hydroxychloroquine data on COVID-19 patients across Italy and eventually other countries. He said he hoped to get the site going in the next few days and would make the data widely available as soon as possible.

Ultimately, Savarino thinks a combination of two or three drugs will be found to be the most effective treatment for COVID-19, like how therapies using multiple drugs have become the standard for treating HIV, he said.