Hydroxychloroquine: WHO suspends clinical trial of drug touted by Trump as 'coronavirus cure' over safety fears

Move comes after a study found use of drug increased risk of death by 34 per cent and risk of serious heart arrhythmias by 137 per cent

A clinical trial of malaria drug hydroxychloroquine has been suspended by the World Health Organisation amid safety concerns, the body's chief has confirmed.

"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. The other arms of the trial are continuing," WHO Director General Tedros Adhanom Ghebreyesus told an online briefing.

The drug has been repeatedly endorsed by a world leaders including Brazil's Jair Bolsonaro and US president Donald Trump — who yesterday said he had just finished a course of the medicine, which he claimed to have been taking as a preventative measure.

The move comes after a study published in the The Lancet medical journal said that the use of the drug increased the risk of death by 34 per cent and a 137 per cent increased risk of serious heart arrhythmias.

“Our large-scale, international, real-world analysis supports the absence of a clinical benefit of chloroquine and hydroxychloroquine and points to potential harm in hospitalised patients with COVID-19,” said the authors of the study.

The same study concluded that patients receiving hydroxychloroquine and an antibiotic faced a 45 per cent increased risk of death and a 411 per cent increased risk of serious heart arrhythmias.

Mr Ghebreyesus emphasised that the concerns about the drug relate only to its use to treat Covid-19, and that both hydroxychloroquine and chloroquine are accepted as generally safe for use in patients with autoimmune diseases or malaria.

The use of the drug by Mr Trump caused a storm of controversy with observers asking why White House medical professionals would allow him to take a drug of questionable efficacy, or if he was even taking it at all.

A memo released by White House physician Commander Sean Conley did not explicitly say that the president had been given a prescription, merely that taking the drug as a preventative measure had been discussed after a valet had test positive for Covid-19.

The Food and Drug Administration issued a dire warning about the use of the drug in late April reminding both healthcare professionals and patients of the risks associated with the drug.

"Hydroxychloroquine and chloroquine have not been shown to be safe and effective for treating or preventing Covid-19. They are being studied in clinical trials for Covid-19, and we authorised their temporary use during the Covid-19 pandemic for treatment of the virus in hospitalised patients when clinical trials are not available," the agency warned.

In Brazil, President Bolsonaro unveiled rules loosening protocols around the use of chloroquine in the treatment of Covid-19, despite a lack of any clinical proof that it is effective in treating the virus or mitigating its effects. The new regulations allow the drug to be given to people with milder symptoms.