Hydroxychloroquine is not used as a treatment for radiation sickness

20th May 2020


Hydroxychloroquine cures Covid-19.


There is some limited evidence that it can work for some patients. It is not licensed as a treatment for Covid-19 in the UK outside of clinical trials.


Hydroxychloroquine is used to treat radiation sickness.


The medicines regulator in the UK says the drug is not used for this.

Claim 1 of 2

A post on Facebook has made the following claim about Covid-19 and the drug hydroxychloroquine:

“Hydroxychloroquine cures this "virus"

It just so happens this is the treatment used for radiation sickness!!”

Facebook user, 14 May 2020

This is wrong. There isn’t good evidence that hydroxychloroquine works at either preventing or curing Covid-19, and the drug is not used to cure radiation sickness either.

Hydroxychloroquine has not been proven to cure Covid-19

Hydroxychloroquine is not licensed to treat Covid-19 in the UK. The Medicines and Healthcare products Regulatory Agency (MHRA), which licenses medicines for use, reiterated this at the end of March, saying: “Until we have clear, definitive evidence that these treatments are safe and effective for the treatment of COVID-19, they should only be used for this purpose within a clinical trial.”

In the UK, this medicine, and a similar drug called chloroquine, are used to treat lupus, rheumatoid arthritis, and certain skin conditions. Chloroquine is also used to treat and prevent malaria.

The evidence that the drug can be effective is limited, and overall the evidence is contradictory. In the US, the Federal Drug Administration issued an Emergency Use Authorization of hydroxychloroquine, meaning the drug can be given to Covid-19 patients in emergencies if they can’t be part of a clinical trial.

However, the FDA says it “is aware of reports of serious heart rhythm problems in patients with COVID-19 treated with hydroxychloroquine or chloroquine” and that the drugs “have not been shown to be safe and effective for treating or preventing COVID-19.”

Hydroxychloroquine is not used to treat radiation sickness

The MHRA told us: “Hydroxychloroquine is not authorised for use as a treatment for radiation sickness and MHRA are not aware of any scientific evidence supporting such use.”

“MHRA have not received any clinical trial requests and there are no trials for this recorded on the public registries.”

Radiation sickness is another name for Acute Radiation Syndrome, which is what happens to people subjected to a large dose of radiation over a short period of time. People who get ARS have usually witnessed a nuclear incident, like the atomic bombings in Japan, the Chernobyl nuclear power plant explosion.

You can’t get ARS gradually over time from things like background radiation, flying, or getting a medical X-ray, for example. The exposure to radiation has to be extremely large, and for a short period of time.

Where might the confusion have come from?

We found one study that has tested to see whether giving mice chloroquine could protect them against low-dose radiation, not ARS. They found that the drug had the potential to be used to treat humans for low-dose radiation issues, but did not prove that this would work in humans.

There may have been some confusion over the fact that there have been some studies into using hydroxychloroquine to cancer patients who are also receiving radiotherapy. Radiotherapy involves using powerful targeted radiation to kill cancer cells. This is not the same as radiation sickness or ARS. The hydroxychloroquine in these studies was being trialled to see if it helped kill cancer cells, not whether it helped side effects of radiotherapy.