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As more studies roll in, little evidence that hydroxychloroquine works

Enlarge / Hospital Corpsman 3rd Class Kimberly Wyss, from Ventura, Calif., dons surgical gloves aboa..

By admin , in Tech , at April 23, 2020

Enlarge / Hospital Corpsman 3rd Class Kimberly Wyss, from Ventura, Calif., dons surgical gloves aboard the hospital ship USNS Mercy (T-AH 19).flickr

A study observing COVID-19 patients has found no evidence that the malaria drug hydroxychloroquine, touted as a possible treatment for COVID-19, made a difference to the chance that patients would need a ventilator. The results also suggested that patients treated with hydroxychloroquine had a higher rate of death than those who werent treated with the drug.

The study was not a randomized clinical trial, which means that the evidence it offers is tentative and should be interpreted with caution. It was also published on preprint server medRxiv, which means it has not yet been peer-reviewed.

But interpreting the evidence with caution does not mean disregarding it completely. This study is one of a growing number telling us that we don't yet know enough about hydroxychloroquine, adding more weight to the argument that we need to wait for better-quality evidence from randomized controlled trials before we start widespread use of a drug with significant side effects.


Some small studies have given us reasons to think that chloroquine and hydroxychloroquine could have potential as treatments for COVID-19. In some cases, the findings come from experiments in cultured cells, which won't necessarily translate directly to using the drugs in sick humans. In others, the findings come from small studies that have critical flaws like using very small groups of patients, having no control group, or excluding patients who died from analysis.

“Normally, such research would be deemed hypothesis-generating at best,” wrote doctors Jinoos Yazdany and Alfred Kim in an opinion piece in the Annals of Internal Medicine. And they were released at the same time that other early studies were finding no evidence that these drugs help COVID-19 patients.

However, early hype—including repeated promotion from President Trump—led to a runaway train of enthusiasm for the drugs. The Food and Drug Administration authorized treatment of COVID-19 patients with chloroquine and hydroxychloroquine despite the lack of good evidence for their efficacy, sparking backlash from former FDA leaders.

These drugs have a range of possible adverse effects, including serious cardiac damage. Using them for critically ill COVID-19 patients therefore not only runs the risk of not helping, but also of actively harming people. The worldwide run on the drugs and resulting shortages are also a problem for patients using them for conditions like lupus, where they have been found to be effective.

A range of clinical trials are now underway to establish whether these drugs are actually beneficial. In the meantime, the FDA authorization means that there is a growing pile of data from patients who have been treated with them.

Testing on the fly

The US Veterans Health Administration is a national system of clinics, hospitals and other medical centers. Because its a single organization, data on patients is gathered in a consistent way, which makes it easier for researchers to compare apples with apples.

A team of researchers used VHA data to track the outcomes of confirmed COVID-19 patients at veterans hospitals who were treated with just hydroxychloroquine, hydroxychloroquine plus an antibiotic, or neither of the drugs. They found that 27.8 percent of the 97 patients treated with just hydroxychloroquine died, compared to 11.4 percent of the 158 patients who werentRead More – Source