Coronavirus patients taking hydroxychloroquine have been linked to an increased risk of death, forcing the World Health Organisation to halt tests of the anti-malarial drug on thousands of infected people.

Chief Tedros Adhanom Ghebreyesus is responding to research which last week uncovered that the drug used to treat other illnesses was not only ineffective but dangerous when used on COVID-19 patients.

Hydroxychloroquine has been touted by the likes of Donald Trump who claimed to have been ingesting it, as well as Clive Palmer who insisted his foundation had bought 32,900,000 doses of it.

Now, 3500 coronavirus sufferers from 17 countries who volunteered to be a test subject as part of the WHO-led international Solidarity Trial are being taken off hydroxychloroquine, at least temporarily.

A decision has been taken to implement “a temporary pause of the hydroxychloroquine arm within the Solidarity Trial while the safety data is reviewed,” Dr Tedros told a press briefing on Tuesday morning (Australian time).

It came after US and Swiss scientists reported in The Lancet journal that hydroxychloroquine and the similar drug chloroquine could lead to higher death rates and heart palpitations.

The medications have not been shown to be effective against COVID-19, they wrote.

Bottles of hydroxychloroquine pills were distributed in hospitals in San Salvador. Photo: Getty

WHO’s trial originally aimed to find out if existing medications that were developed against malaria, HIV, Ebola and multiple sclerosis could help to treat COVID-19.

While WHO has been advising against using malaria drugs against the coronavirus as long as the trials are still under way, the Brazilian Health Ministry last week authorised hydroxochloroquine for treating mild as well as severe COVID-19 cases.

While Mr Trump has made headlines for promoting and taking hydroxychloroquine as a preventive drug against COVID-19, he said on Wednesday that he would soon stop using it.

Dr Tedros stressed that hydroxychloroquine and chloroquine are safe for treating patients with malaria and certain autoimmune diseases.

Researchers from Melbourne’s Walter and Eliza Hall Institute plan to put hydroxychloroquine to the test, with healthcare workers to be recruited for a volunteer trial.

The Institute’s Professor Ian Wicks said there were other trials underway assessing the drug’s as a treatment, but Covid Shield would be the first to test it as a prophylaxis, or prevention, against the flu-like illness sweeping the globe.

-with AAP