Note: This post has not been updated since March and thus some of the information contained here may not reflect the current state of knowledge. Please refer to the World Health Organization or your local public health agencies for the most up-to-date information on COVID-19.
All of a sudden, the medication chloroquine is in the news for its potential role in managing COVID-19. This post will look at what’s known, and not known, about potential treatments for the novel coronavirus.
In the news
On March 19, U.S. President Donald Trump announced that the Food and Drug Administration (F.D.A.) had approved the medication chloroquine to treat COVID-19. However, the F.D.A. hasn’t approved it for that particular indication. It was already on the market, as it was approved for treating malaria.
On March 20, Dr. Anthony Fauci, the head of the National Institute of Allergy and Infectious Diseases, stated that there wasn’t clear evidence that chloroquine could treat the coronavirus, although at the same press briefing President Trump said that he was a “big fan” of the drug and he “comes from a very positive school” with regards to chloroquine. Given that he has no public health training, take that with a grain of salt.
Chloroquine has been around for years. It has anti-malarial activity, but it’s seldom used now for malaria as resistance has developed in most parts of the world. Like any medication, it has potential side effects, but given it’s been around for a while, its side effect profile is well known. It can potentially cause psychosis, although the risk isn’t as high as with the related drug mefloquine (Lariam).
An expert consensus statement from a group of researchers in China that was published on March 12 indicated that chloroquine was used because of its antiviral properties and it “might improve” patient outcomes, so they were recommending that a 10-day course of chloroquine be given to patients with mild, moderate, or severe novel coronavirus pneumonia.
A paper by Colson et al. elaborated on the data used by the Chinese consensus group and stated that early findings from over 100 patients, chloroquine had positive clinical effects without any serious side effects.
A letter by a group of Chinese researchers to the editor of Cell Discovery, published March 18, reported some new research findings using chloroquine and a similar drug, hydroxychloroquine (Plaquenil), which is used to treat autoimmune conditions like rheumatoid arthritis. In African green monkey cell cultures, both chloroquine and hydroxychloroquine were effective against the novel coronavirus. That’s promising, but not enough to know if there will be clinical effectiveness in humans.
On March 17, an expert consensus group in Italy released a set of recommendations for managing COVID-19, which included a 10-day course of either chloroquine or hydroxychloroquine.
There is an experimental antiviral drug, remdesivir, that has also demonstrated activity against the novel coronavirus, but phase III clinical trials have just been started, so it’s unlikely to be widely available soon. Several clinical trials are underway in China, and the National Institutes of Health are sponsoring a trial in the U.S.
A vaccine has been developed that is currently in phase I clinical trials at Kaiser Permanente Washington Health Research Institute in Seattle, Washington, funded by the National Institutes of Health. If you happen to live in the Seattle area, they’re recruiting healthy volunteers.
Potential supply issues
Because chloroquine isn’t often used, there’s not a lot of it kicking around, so supply could be an issue. Bayer announced on March 19 that it would be donating 3 million chloroquine to the U.S. government, which is a positive step. If chloroquine and hydroxychloroquine do prove to be effective, governments need to play it right or prices could go through the roof.
We’ve already seen hoarding behaviour, so is everyone and their dog going to be rushing out to get a supply of these drugs if they turn out to be effective? There’s a lot more hydroxychloroquine on the market than chloroquine, but regardless, there’s not enough for everyone, so there will need to be some type of system.
Where we are now
It’s good to know that there are some things coming down the pipe that might work. But we’re still very much at the “might work” stage. Since China got the virus first, they’re ahead of the rest of us in terms of research, so the findings of the clinical trials they have underway are going to be really important.
For now, though, we need to let the researchers and clinicians do their thing, and follow what our public health departments are directing in terms of social distancing and other precautions.
Addendum – March 21/20
President Trump announced on Twitter this morning:
HYDROXYCHLOROQUINE & AZITHROMYCIN, taken together, have a real chance to be one of the biggest game changers in the history of medicine. The FDA has moved mountains – Thank You! Hopefully they will BOTH (H works better with A, International Journal of Antimicrobial Agents)…..
…be put in use IMMEDIATELY. PEOPLE ARE DYING, MOVE FAST, and GOD BLESS EVERYONE!
This doesn’t actually have to do with the FDA. A group of French researchers has submitted a paper to the International Journal of Antimicrobial Infections with early results of a trial that they’re running. The trial compares COVID-19 patients treated with hydroxychloroquine to a control group with COVID-19 that did not receive the drug. A segment of the hydroxychloroquine group also received azithromycin in an attempt to prevent bacterial infection on top of the viral infection.
The results that have just been released involved 16 control group patients, 14 patients receiving just hydroxychloroquine, and 6 patients receiving the combination of hydroxychloroquine and azithromycin. The six patients receiving the combination did better, and got better faster, than the hydroxychloroquine alone patients, who in turn did better than the control group.
So, we’re talking about six patients. It’s positive news, but a very small number. And before we go handing them out in a Pez dispenser, it’s worth noting that there is a risk of serious heart rhythm abnormalities with the combination of the two drugs. The patients in the French study were in hospital and had close cardiac monitoring.
The French trial is ongoing, and as the numbers grow the role of these drugs will start to become clearer.
There’s more on public health and COVID-19 in The Science Corner.
I’ve put together a COVID-19 coping toolkit with some resources to help with managing the stress of the current pandemic.
- Business Insider: Trump undercuts his top infectious disease expert on whether an unapproved treatment for coronavirus is safe, a day after the FDA said it had not yet been approved
- CNN: Fact check: Trump wrongly claims FDA ‘approved’ drug chloroquine to treat the coronavirus
- Colson, P., et al. (2020). Chloroquine and hydroxychloroquine as available weapons to fight COVID-19 [pre-proof]. International Journal of Antimicrobial Agents.
- Gautret et al. (2020) Hydroxychloroquine and azithromycin as a treatment of COVID‐19: results of an open‐label non‐randomized clinical trial. International Journal of Antimicrobial Agents – In Press 17 March 2020 – DOI : 10.1016/j.ijantimicag.2020.105949
- Liu, J., et. al. (2020). Correspondence: Hydroxychloroquine, a less toxic derivative of chloroquine, is effective in inhibiting SARS-CoV-2 infection in vitro. Cell Discovery 6, Article 16.
- Multicenter collaboration group of Department of Science and Technology of Guangdong Province and Health Commission of Guangdong Province for chloroquine in the treatment of novel coronavirus pneumonia. (2020). Expert consensus on chloroquine phosphate for the treatment of novel coronavirus pneumonia. English abstract on PubMed.
- National Institutes of Health. (2020). News release: NIH clinical trial of investigational vaccine for COVID-19 begins.
- Nicastri, E., et al. (2020). National Institute for the Infectious Diseases “L. Spallanzani” IRCCS. Recommendations for COVID-19 Clinical Management. Infectious Disease Reports, 12(8543), 3-9.