Hydroxychloroquine is a medication that doctors prescribe to treat a variety of conditions, including malaria, arthritis, and lupus.

Recently, some doctors had been using hydroxychloroquine to treat severe cases of COVID-19 in hospitalized patients. Its use for this purpose has been controversial and conflicting, with some researchers reporting heart problems among those taking the drug.

The Food and Drug Administration (FDA) have now withdrawn the emergency use of hydroxychloroquine for COVID-19 treatment.

The National Institutes of Health (NIH) have also stopped a clinical trial evaluating the drug’s safety and efficacy in treating COVID-19. The researchers judged that while the treatment caused no harm to patients, it was unlikely to be beneficial.

In this article, we look at the available research on hydroxychloroquine as a treatment for COVID-19. We also discuss other potential treatments for this disease.

Stay informed with live updates on the current COVID-19 outbreak and visit our coronavirus hub for more advice on prevention and treatment.

What is hydroxychloroquine?

The FDA do not approve hydroxychloroquine as a treatment option for COVID-19.
Image credit: GEORGE FREY/AFP via Getty Images.
Hydroxychloroquine, or hydroxychloroquine sulfate, is an antimalarial medication and a disease-modifying antirheumatic drug (DMARD).

DMARDs are drugs that slow the progression of certain autoimmune diseases, such as:

rheumatoid arthritis
juvenile idiopathic arthritis
lupus
It is not clear why hydroxychloroquine effectively treats autoimmune conditions.

Experts believe that the drug alters cell communication in the immune system. This action inhibits the immune system response that ordinarily triggers inflammation and cell damage.

Again, this may explain why some doctors have tried using hydroxychloroquine to treat severe cases of COVID-19. The theory is that the drug helps stop the immune system from going into overdrive and attacking the body’s organs.

However, it is not clear whether hydroxychloroquine has any effect against COVID-19.

Research: Positive vs. negative outcomes
Some doctors and researchers have been using hydroxychloroquine to treat severe cases of COVID-19.

We outline some of the key findings from these trials below.

Studies reporting positive outcomes
Researchers published an initial study in March 2020. It indicated that a combination of hydroxychloroquine and the antibiotic azithromycin might reduce the viral load of SARS-CoV-2, the virus that causes COVID-19.

The viral load is the amount of virus in the body. Doctors usually associate higher viral loads with more severe symptoms.

However, the above study only had a small number of participants, and experts have criticized other aspects of its design.

A Henry Ford Health System study suggests that taking hydroxychloroquine can lower the risk of death from COVID-19.

Among a cohort of more than 2,500 patients hospitalized with the illness, 13% of those who received hydroxychloroquine died, compared with 26% of those who did not receive the drug, the study authors report.

However, the team did not control for some significant confounding variables, such as patient age; 64% of patients who did not receive hydroxychloroquine were over 65, while only 49% of those who received the drug were older than 65.

Other variables, such as the ethnicity, were also notably different among the patient groups.

Studies reporting negative outcomes
A further small study evaluated the effects of hydroxychloroquine and azithromycin on patients hospitalized with COVID-19. The majority of these individuals had co-occurring or “comorbid” conditions, such as obesity, cancer, or HIV.

There was no evidence to suggest that the drug treatment worked for the participants. Notably, one patient had to stop treatment because of a hydroxychloroquine side effect that can lead to fatal heart problems.

Another study investigated the hospital records of 368 patients admitted with COVID-19.

The findings indicate that those taking hydroxychloroquine as a stand-alone drug treatment were at higher risk of death than those who did not take hydroxychloroquine.

This was also the case when the researchers compared them with those who took a combination of hydroxychloroquine and azithromycin.

Importantly, this study has not yet undergone peer review by other scientists.

Studies reporting no benefit
In early June 2020, researchers in the United Kingdom published results from the largest trial to date on hydroxychloroquine.

Of the 4,674 hospitalized patients who took part in the trial, 1,542 received hydroxychloroquine, while 3,132 received standard treatment.

The percentage of people who died after 4 weeks was 25.7% for those receiving the drug and 23.5% for those receiving standard treatment.

These data suggest that there is no meaningful benefit to taking hydroxychloroquine for those with active COVID-19 disease.

Nor does hydroxychloroquine appear to protect healthy people from disease onset after exposure to the virus.

A randomized, double-blind, placebo-controlled trial of 821 participants suggests that the medication does not protect those at high risk of COVID-19 infection.

The NIH were running a clinical trial to evaluate the safety and effectiveness of using hydroxychloroquine to treat adults hospitalized with COVID-19. However, the NIH halted the trial after the initial data suggested that the drug was no more effective than a placebo.

What is the consensus?
Overall, the findings from the above studies suggest that there is limited evidence for the use of hydroxychloroquine for the prevention or treatment of COVID-19.

A meta-analysis of 23 studies investigating the use of hydroxychloroquine for COVID-19 supports this view.

The meta-analysis concludes that the evidence on the benefits and harms of the drug is both weak and conflicting.