Donald Trump has reignited a controversy over the antimalarial drugs chloroquine and hydroxychloroquine after telling reporters he was taking the latter to protect himself against coronavirus. What do we know about these drugs?
What is hydroxychloroquine?
Hydroxychloroquine, which Trump says he has been taking for about two weeks, was developed as an antimalarial but it is also used to treat conditions like lupus, an anti-immune disease, and arthritis, where it can help combat inflammation. It has been licensed for use in the US since the mid 1950s and is listed by the World Health Organization as an "essential" medicine.
What is the link to Covid-19?
Researchers have been interested in chloroquines as an anti-viral agent for some time. A study in Virology Journal in 2005 found that chloroquine inhibited the closely related Sars virus in primate cells in lab conditions.
However, evidence for the effectiveness of hydroxychloroquine in recent human trials during the coronavirus pandemic has been at best inconclusive, with some suggestions that it could worsen the outcome of severe cases.
The WHO is looking at whether hydroxychloroquine could be an effective Covid-19 treatment, while the US National Institutes for Health is also running a clinical trial to establish whether the drug, administered together with the antibiotic azithromycin, can prevent hospitalisation and death from Covid-19.
In recent days, enthusiasm about hydroxychloroquine has been boosted by a study, which has yet to be peer-reviewed, that looked at the combination of hydroxychloroquine, the antibiotic azithromycin and zinc supplements.
It showed that patients who received the three-drug combination vs the two-drug combination of hydroxychloroquine and azithromycin were 44 per cent less likely to die than the second group. Joseph Rahimian, a co-author of the study, pointed out that the study's findings were limited to the possible promise of zinc, not of hydroxychloroquine.
What’s the state of the current evidence?
In May, the British Medical Journal reported on a randomised (although still problematic) clinical trial in China that found little evidence hydroxychloroquine worked, with serious adverse events noted in two patients.
A second study reported in the BMJ last week on a French trial also concluded that hydroxychloroquine does not significantly reduce admission to intensive care or improve survival rates in patients hospitalised with pneumonia owing to Covid-19. Overall, 89 per cent of those who received hydroxychloroquine survived after 21 days, compared with 91 per c ent in the control group.
The US Food and Drug Administration in a safety alert issued on April 24th warned that it had received reports that hydroxychloroquine and chloroquine could have serious side-effects and that the drugs should be taken only under the close supervision of a doctor in a hospital setting or a clinical trial.
What are the risks in taking hydroxychloroquine?
There are a number of side-effects. The most serious is that it can interfere with the rhythm of the heart. Other side-effects include headache, dizziness, nausea, vomiting, stomach pain, skin rash or itching or hair loss. Research published by the Mayo Clinic has suggested that “off-label” repurposing of drugs such as hydroxychloroquine could lead to “drug-induced sudden cardiac death”.
Although Trump’s official physician has said he was in “very good health” at his last official check-up, the president is 73 and his recorded weight would put him in a BMI category of “clinically obese”.
So why is Trump taking it?
Despite there being no conclusive body of evidence that it can be effective when used to prevent contracting coronavirus, the president apparently decided in conversation with the White House physician Sean P Conley that it was worth the risks.
“After numerous discussions he and I had for and against the use of hydroxychloroquine we concluded the potential benefit from treatment outweighed the relative risks,” Conley wrote.
It is probably worth pointing out that Conley, a naval doctor, trained initially as an osteopath and then in emergency medicine, serving as research director at Portsmouth Navy Department of Emergency Medicine prior to his assignment to the White House medical unit.
For his part, Trump, despite the FDA and other warnings, said: “I think it’s good. I’ve heard a lot of good stories. And if it’s not good, I’ll tell you right. I’m not going to get hurt by it. It’s been around for 40 years.”
Have we been here before?
Yes. Trump has a history of personally advocating for the use hydroxychloroquine, which he has described as a potential “game-changer”. Although it has been reported that Trump has a small stake in a French company that makes hydroxychloroquine via an investment fund, this seems to be about Trump’s own hunches and his desire to be both proved right and protected against the disease.
On Monday, he also claimed lots of doctors were using the drug prophylactically and cited letters he had received from members of the public. As Paul Waldman, a columnist in the Washington Post, has suggested, this is more about Trump's psychology than anything else.
“Trump compensates for his own insecurity by working to convince himself and everyone else that the experts don’t know what they’re talking about, and he knows more than them about everything,” Waldman has written. – Guardian
