There’s a high demand for it and even US President Donald Trump and Brazilian President Jair Bolsonaro have openly admitted to taking it. But hydroxychloroquine, a drug normally used for malaria, is far too risky to be used as a treatment for the novel coronavirus, the World Health Organization says.

The World Health Organization (WHO) was carrying out clinical trials of hydroxychloroquine as a potential treatment for COVID-19 but has now decided to suspend them in all countries, following a study last week that warned over the risks of taking the drug and its lack of effects against COVID-19.

WHO chief Tedros Adhanom Ghebreyesus attended a virtual press conference during which he explained that the executive group of the so-called Solidarity Trial, in which hundreds of hospitals across several countries have enrolled patients to test several possible treatments for the novel coronavirus, had as a precaution suspended trials of the drug.

“The Executive Group has implemented a temporary pause of the hydroxychloroquine arm within the Solidarity Trial while the safety data is reviewed by the Data Safety Monitoring Board,” Tedros said. “The other arms of the trial are continuing,” he stressed.

Tedros said the concern related only to the use of hydroxychloroquine for COVID-19, adding that the drugs were accepted treatments for people with malaria and auto-immune diseases. Other treatments in the WHO’s solidarity trial, including the experimental drug remdesivir and an HIV combination therapy, are still being pursued.

Last week, a study with 96,000 coronavirus patients said there were no benefits to treating coronavirus patients with hydroxychloroquine, and that taking it might even increase the number of deaths among those in a hospital with the disease. The researchers warned the drug should not be used outside of clinical trials.

“We were unable to confirm a benefit of hydroxychloroquine when used alone or with a macrolide, on in-hospital outcomes for COVID-19. Each of these drug regimens was associated with decreased in-hospital survival and an increased frequency of ventricular arrhythmias when used for treatment of COVID-19,” the researchers wrote.

Researchers from the American College of Physicians (ACP) had already said that the drug should only be used to treat hospitalized COVID-19 positive patients in the context of a clinical trial following shared and informed decision-making between clinicians and patients.

Hydroxychloroquine is used to manage other major illnesses but because of all the hype, it is now in short supply in the United States. The drug also has known (and harmful) side-effects in non-COVID patients such as cardiovascular problems, diarrhea, abnormal liver function, rashes, headaches, ocular issues, and anemia.

In late March, the US Food and Drugs Administration (FDA) granted “emergency use” authorization for these drugs in the treatment of COVID-19 for a limited number of cases. That does not mean the FDA is saying they definitely work. But it does mean that in specific circumstances, hospitals can use the drugs on COVID-19 patients — however, in light of these recent findings it’s highly unlikely that hydroxychloroquine will be administered to coronavirus patients anytime soon.

President Donald Trump claimed in mid-May that he was taking daily doses of hydroxychloroquine. Trump said he has taken the antimalarial drug after consulting the White House doctor, although he stopped short of saying his physician had actually recommended the drug.

Trump said he hadn’t been exposed to coronavirus, and he started taking the drug because he had heard from frontline responders who sent him letters saying they were taking it preventatively. “Here’s my evidence: I get a lot of positive calls about it,” Trump said.