The World Health Organization announced Monday it was suspending the clinical trials of hydroxychloroquine as a potential treatment for the COVID-19 after a study published in a medical journal last week claimed that the drug can increase the risk of death among coronavirus patients.

A study published in The Lancet medical journal last week suggested the drug could increase the risk of death among COVID-19 patients, WHO chief Tedros Adhanom Ghebreyesus told a virtual press conference.

Tedros said the executive group of the so-called Solidarity Trial, in which hundreds of hospitals across the world have enrolled patients to test several possible treatments for the novel coronavirus, had suspended trials using that drug as a precaution.

“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.”

Hydroxychloroquine is normally used to treat arthritis but public figures including US President Donald Trump have backed the drug as a virus treatment, prompting governments to bulk buy.

Trump said last week he was taking the drug as a preventative measure, but in an interview aired on Sunday on Sinclair Broadcasting he said he had completed his course.

“Finished, just finished,” Trump said. “And by the way, I´m still here. To the best of my knowledge, here I am.”

Brazil´s health minister also recommended last week using hydroxychloroquine, as well as the anti-malarial chloroquine, to treat even mild COVID-19 cases.

The Lancet study found that both drugs could produce potentially serious side effects, particularly heart arrhythmia.

And neither drug helped patients hospitalised with COVID-19, according to the study, which looked at the records of 96,000 patients across hundreds of hospitals.