There's No Quality Data Showing Hydroxychloroquine and Chloroquine Can Help COVID-19 Patients, Scientists Say

There is no high-quality data showing that taking the anti-malarial drugs hydroxychloroquine and chloroquine can help COVID-19 patients, the authors of a review of existing evidence have warned. As such, they said the drugs should only be used to treat patients taking part in carefully designed clinical trials.

To conduct the review, lead author Dr. Mark Poznansky, director of the Vaccine and Immunotherapy Center at Massachusetts General Hospital, and colleagues looked at studies and anecdotal reports on the drugs' use in COVID-19 and other conditions. They released their findings in FASEB Journal, published by the Federation of American Societies for Experimental Biology.

"There continues to be no high-quality clinical data showing a clear benefit of these agents" for COVID-19, the authors wrote.

Among their conclusions was that the drugs "have the potential to cause harm," including serious heart problems when combined with other medicines. One pre-print study cited by the researchers which has not been peer reviewed included more than 950,000 patients who took hydroxychloroquine. When combined with the antibiotic azithromycin, they found patients had a 15 to 20 percent higher risk of developing chest pain or heart failure in the first month of treatment, with their risk of dying of a heart problem doubling.

There are currently no specific drugs to treat COVID-19, which has sickened over 3 million people worldwide, according to Johns Hopkins University. 228,057 people have died of the disease, and almost 1 million have survived. In the five months since the COVID-19 pandemic started, the U.S. has emerged as the country with the most known cases, as the graphic below by Statista shows.

covid19, coronavirus, statista
A graph showing the countries with the most known COVID-19 cases. Statista

Back in March, the Food and Drug Administration (FDA) issued the first Emergency Use Authorization in relation to COVID-19, stating that the two anti-malaria drugs could be prescribed to teens and adults with the disease. President Donald Trump has meanwhile repeatedly touted the drug.

The team behind the review said: "As hospitals around the globe have filled with patients with COVID-19, front line providers remain without effective therapeutic tools to directly combat the disease. The initial anecdotal reports out of China led to the initial wide uptake of HCQ [hydroxychloroquine] and to a lesser extent CQ [chloroquine] for many hospitalized patients with COVID-19 around the globe.

"As more data have become available, enthusiasm for these medications has been tempered. Well designed, large randomized controlled trials are needed to help determine what role, if any, these medications should have in treating COVID-19 moving forwards."

The researchers also noted the antimalarial drugs have a "potent" effect on the body's immune response. That is why hydroxychloroquine is used to treat autoimmune disorders such as rheumatoid arthritis and lupus. This partly gave rise to the hope that the drugs may be useful for COVID-19 patients, the reviewers explained. However, the drugs may in fact dampen the body's natural immune response, they explained.

Poznansky told Newsweek there is no data from animals or humans suggesting hydroxychloroquine should be used to treat COVID-19, and data from newly emerging clinical trials suggests that patients with this disease don't benefit from taking the drug.

"It turned out that the antiviral data for hydroxychloroquine was weak at best and had all been generated in the test tube," said Poznansky.

The team wrote: "For all these reasons, and in the context of accumulating preclinical and clinical data, we recommend that HCQ [hydroxychloroquine] only be used for COVID-19 in the context of a carefully constructed randomized clinical trial.

"If this agent is used outside of a clinical trial, the risks and benefits should be rigorously weighed on a case-by-case basis and reviewed in light of both the immune dysfunction induced by the virus and known antiviral and immune modulatory actions of hydroxychloroquine."

covid19, coronavirus, getty
Bottles of hydroxychloroquine pills are shown in San Salvador on April 21, 2020, amid the COVID-19 outbreak. YURI CORTEZ/AFP via Getty Images

Poznansky, who is also an attending physician of infectious diseases medicine at Massachusetts General Hospital, said he wanted to review the safety and efficacy of the medicines after he saw many patients with moderate and severe forms of COVID-19 were on hydroxychloroquine "were not doing well for a number of reasons." He wanted to see whether the scientific literature could help to explain the role the drugs might be playing.

Considering how the treatment of COVID-19 patients should be approached, Poznansky said researchers should look carefully at data on pre-existing drugs being considered to treat the disease "to make doubly sure" that there is no indication that they will be ineffective or pose a risk.

Poznansky said the article is a cautionary note against instituting the wholesale use of unproven or untrialed medicines "in an entirely new infection which is currently incompletely understood. Remembering always that at first in medicine–do no harm."

"We know that medical history is littered with administered medical treatments, popularized in the public and medical arenas, that either did no good or worse were ultimately shown to do harm."

He added: "There has never been a more important time than during this COVID-19 pandemic to remember and emphasize the importance of clinical trials to guide clinical decision making and to emphasize the principles governing this including—respect of persons, beneficence and justice."

Andrew Preston, reader in microbial pathogenesis at the University of Bath, U.K., who did not work on the review, told Newsweek only a few controlled trials have been conducted on using hydroxychloroquine and he also believed "these have yet to show any clear therapeutic effect.

"I think that initially, much of the use was on the basis that its been used for decades in people and is thus safe, and so 'might do some good, wont do any harm.' However, one of the things to come out of the trials is that it does cause adverse effects, and some of these can be serious," he said.

Preston added: "There are other large controlled trials underway. They should start producing data soon. Then we'll have a much better idea of any therapeutic effect."

Centers for Disease Control and Prevention Advice on Using Face Coverings to Slow Spread of COVID-19

  • CDC recommends wearing a cloth face covering in public where social distancing measures are difficult to maintain.
  • A simple cloth face covering can help slow the spread of the virus by those infected and by those who do not exhibit symptoms.
  • Cloth face coverings can be fashioned from household items. Guides are offered by the CDC. (
  • Cloth face coverings should be washed regularly. A washing machine will suffice.
  • Practice safe removal of face coverings by not touching eyes, nose, and mouth, and wash hands immediately after removing the covering.

World Health Organization advice for avoiding spread of coronavirus disease (COVID-19)

Hygiene advice

  • Clean hands frequently with soap and water, or alcohol-based hand rub.
  • Wash hands after coughing or sneezing; when caring for the sick; before, during and after food preparation; before eating; after using the toilet; when hands are visibly dirty; and after handling animals or waste.
  • Maintain at least 1 meter (3 feet) distance from anyone who is coughing or sneezing.
  • Avoid touching your hands, nose and mouth. Do not spit in public.
  • Cover your mouth and nose with a tissue or bent elbow when coughing or sneezing. Discard the tissue immediately and clean your hands.

Medical advice

  • Avoid close contact with others if you have any symptoms.
  • Stay at home if you feel unwell, even with mild symptoms such as headache and runny nose, to avoid potential spread of the disease to medical facilities and other people.
  • If you develop serious symptoms (fever, cough, difficulty breathing) seek medical care early and contact local health authorities in advance.
  • Note any recent contact with others and travel details to provide to authorities who can trace and prevent spread of the disease.
  • Stay up to date on COVID-19 developments issued by health authorities and follow their guidance.

Mask and glove usage

  • Healthy individuals only need to wear a mask if taking care of a sick person.
  • Wear a mask if you are coughing or sneezing.
  • Masks are effective when used in combination with frequent hand cleaning.
  • Do not touch the mask while wearing it. Clean hands if you touch the mask.
  • Learn how to properly put on, remove and dispose of masks. Clean hands after disposing of the mask.
  • Do not reuse single-use masks.
  • Regularly washing bare hands is more effective against catching COVID-19 than wearing rubber gloves.
  • The COVID-19 virus can still be picked up on rubber gloves and transmitted by touching your face.