Donald Trump is being treated with a cheap steroid that only works on severely ill coronavirus patients, sparking confusion about the true nature of the US President's condition.
Over the weekend, his medical team revealed that he had been put on a course of dexamethasone, which became the first drug scientifically proven to benefit people with Covid-19 in June.
But the Oxford University trial that made the discovery only found the £5 ($6.45) tablets were effective on patients with low oxygen levels who were on the verge of needing mechanical ventilation.
There has been confusion about the seriousness of the president's health since he was admitted to hospital with the virus on Friday after his oxygen levels plummeted below normal levels.
Mr Trump's doctors have claimed he is now symptom-free and could even be discharged from hospital today, but this was contradicted by White House chief of Staff, Mark Meadows, who described the president's illness as 'very concerning'.
Scientists in the UK and US have today described the decision to give Mr Trump dexamethasone as potentially 'dangerous' because it has no effect on people with mild illness and may even make their condition worse.
Professor Paul Hunter, a medical and infectious diseases expert at the University of East Anglia in England, told MailOnline that giving dexamethasone to Mr Trump too early could shut down his immune system and allow the virus to cause more severe illness. He said results from trials of the steroid on Covid-19 sufferers suggested it could actually increase death in people given it prematurely.
Nicholas Christakis, a physician and sociologist at Yale University, said the president was 'either sicker than they have let on' or his doctors were being 'irresponsible'.
News Mr Trump is being treated with a drug reserved for the sickest of Covid-19 patients will fuel concerns about the true condition of the president, who, at 74, falls into the most at-risk age group.
Steroids in high doses and over long periods of time also can lead to serious changes in mental status that include delirium, hallucinations and confusion. More commonly, the drugs can cause heartburn, anxiety, high blood pressure, muscle weakness and insomnia.
One eminent British medical expert, who did not want to be named, questioned whether Mr Trump's physician - Dr Sean Conley - was properly qualified to lead a team of 20 medical staff, who have different specialties, to treat the highly infectious disease. Dr Conley trained as an osteopath, which focuses on treating problems in the the muscles and joints.
They told MailOnline: 'I don't know if there is different training in the US, but in this country you wouldn't want an osteopath treating infectious diseases. You'd want a team of intensive care medics and specific infectious diseases doctors, like Boris had when he got it [Covid].'
Yesterday, Mr Trump posted an upbeat video praising his doctors at the Walter Reed National Military Medical Center in Bethesda, Maryland, and claiming he was in good health. The president said his battle with the virus had been a 'very interesting journey' and that he had 'learned a lot about Covid'.
Despite looking a little paler than normal, Mr Trump spoke energetically and did not appear to have any of the tell-tale signs of the disease, such as trouble breathing or a continuous cough.
Dr Conley told reporters yesterday that Mr Trump could be discharged from hospital later today and may be allowed to continue his treatment back at the White House.
But Mr Christakis said he would be 'mystified' if the president was out of hospital on Monday, adding: 'It doesn't fit all the other facts of his condition, as disclosed. And it sets up bad optics or bad medical care.'
The Yale expert continued: 'If he is not discharged, it will signal that he is not doing as well as hoped or has had a reversal of his claimed trajectory. Of course [the] White House has medical facilities, but a return to hospital after discharge, if required soon, would be bad medicine and bad politics.'
Mr Trump was suffering from a high fever on Friday when he was first admitted, doctors said at the time, and twice his oxygen saturation levels dropped to 93 per cent over the weekend - the usual range being 95 to 100 per cent.
Some medics consider patients to have severe Covid-19 if their oxygen levels drop below 94 per cent, but others put the threshold at 90. Physicians said the incumbent was administered oxygen at the White House on Friday and revealed he was put on a course of dexamethasone.
Experts have questioned whether they had given him dexamethasone too quickly, or whether the president was far sicker than has been publicly acknowledged.
Mr Christakis said on Twitter: 'Either he is sicker than they have let on and clearly warrants dexamethasone, or he's not so sick, and therefore putting him on dexamethasone is irresponsible.
'I think [Mr Trump] is probably sicker (and for longer) than they are telling us. And if, as a 74 year old obese man, he has gotten that sick this fast, there is a high chance that he will continue to worsen. He could be in ICU within 48 hrs. It is hard to say given lack of transparency.'
Professor Peter Openshaw, an expert in experimental medicine at Imperial College London and a member of the UK Government's Scientific Advisory Group for Emergencies, described the decision to put Trump on dexamethasone as 'unusual', if his illness is as mild as the president's doctors claim.
He told the Guardian: 'It's normally reserved for people who have had symptoms for a week or more and who are going into respiratory failure. It would be unusual to be starting steroids with a relatively short duration of illness.'
Dr Thomas McGinn, the physician-in-chief at Northwell Health, the largest health care provider in New York State, told the NY Times: 'The dexamethasone is the most mystifying of the drugs we're seeing him being given at this point.
'It raises the question: Is he sicker than we're hearing, or are they being overly aggressive because he is the president, in a way that could be potentially harmful?'
The World Health Organization (WHO) says dexamethasone should only be given to patients with 'severe and critical Covid-19' - guidance which appears to be open to interpretation.
The National Institutes of Health goes one step further, specifying that the drug is only for people who require a mechanical ventilator to help them breathe, or who need oxygen support.
An Oxford University study of dexamethasone found the cheap steroid only helped those who had been sick for more than a week. Mr Trump is thought to have only picked up the virus late last week.
The RECOVERY trial, which involved 6,000 Covid-19 patients, found the steroid reduced the risk of death by one-third among patients on mechanical ventilators and by one-fifth among patients receiving oxygen.
The discovery saw the UK Government immediately approve the steroid to be available on the NHS the next day.
But the drug — given as either an injection or once-a-day tablet on the NHS — had no benefit for people who were hospitalised with the virus but did not require oxygen.
Professor Hunter said there was some evidence it may increase deaths in people who take it too early, although researchers were not able to prove it beyond doubt.
Professor Hunter told MailOnline: 'It's not just irresponsible to give dexamethasone too early, it's dangerous.
'I do not know what other factors may have effected the decision to use dexamethasone if it was indeed used, but clearly I do not have access to special knowledge about the presidents current health status.'
The East Anglia University expert added: 'Steroids like dexamethasone suppress your immune system. For viruses like Covid-19, this has a good side and a bad side.
'The damage and deaths in most patients is not because of the virus itself, it's because of the immune system fighting the virus.
'For some people the immune system does not go into overdrive and manages to beat the virus.
'But in other, the immune system goes absolutely crazy, which causes deadly blood clots to form everywhere. It's only these people who should be given steroids.
'If you give steroids too early, you suppress the immune system at the point it might be doing more harm than good.'
Professor Hunter's concerns about dexamethasone stem from results of the RECOVERY trial, which found mortality rates among patients not receiving oxygen was 3 per cent higher in the patients who had dexamethasone compared to normal care.
The steroid prevents the release of substances in the body that cause inflammation, a nasty Covid-19 complication that makes breathing difficult. In seriously unwell patients, the lungs become so inflamed they struggle to work.
But it comes with a host of side effects, including vomiting, heartburn, anxiety, high blood pressure, muscle weakness and insomnia - all of which could be made worse in older, vulnerable patients with weakened immune systems.
Dexamethasone, first created in the 1950s, is usually given to treat ulcerative colitis, arthritis and some types of cancer.
It is already licensed and proven to be safe, meaning it can be used in human patients immediately, and is a generic drug, meaning it can be manufactured cheaply and en masse by companies all over the world.
Scientists said that up to 5,000 lives could have been saved in the UK if they had known about the effectiveness of the drug at the start of the pandemic.
Mr Trump's physician, Dr Sean Conley, told reporters outside the Walter Reed Medical Center in Maryland on Sunday that the president could be discharged from hospital as soon as Monday as he continues to recover from coronavirus.
Dr Conley said: 'Thursday night into Friday morning when I left the bedside, the president was doing well, with only mild symptoms and his oxygen was in the high 90s.
'Late on Friday morning when I returned to the bedside, the president had a high fever and his oxygen levels were transiently dipping below 94 per cent.
'Given these two developments, I was concerned about rapid progression of the illness. I suggested we try some supplemental oxygen, to see how he'd respond.
'He was fairly adamant he didn't need it. He was not short of breath, he was just tired and he had the fever - that was about it.'
Dr Conley was also quizzed on why on Saturday he refused to admit the president had been given supplemental oxygen at the White House on Friday, when his chief of staff Mark Meadows told reporters medics were 'very concerned' about his vital signs before he arrived at Walter Reed.
He said he was 'trying to reflect the upbeat attitude of the team' and 'didn't want to give any information that might steer the course of illness in another direction'.
Dr Conley added that 'in doing so, [it] came off like we were trying to hide something, which wasn't necessarily true'.
Former UK US ambassador Sir Christopher Meyer today accused the White House of giving 'conflicting messages' about Mr Trump's health.
The RECOVERY trial saw a total of 2,104 patients randomised to receive 6mg of dexamethasone once a day, either by mouth or by intravenous injection for 10 days.
Their outcomes were compared with 4,321 patients given standard care alone, which involves painkillers and, in some cases, antibiotics.
For patients on ventilators, the drug cut the risk of death from 40 per cent to 28 per cent. In patients who required oxygen, the risk was reduced from a quarter to a fifth.
Professor Martin Landray, lead researcher, said dexamethasone could have saved up to 5,000 lives if it was used throughout the UK's crisis.
He said: 'If you were to design a drug that treats coronavirus, this would be exactly how you'd hope it works.'
© Associated Newspapers Ltd.