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Coronavirus and hydroxychloroquine: What do we know? Coronavirus and hydroxychloroquine: What do we know?
(7 days later)
There's a lot of interest in using hydroxychloroquine and chloroquine as potential treatments for coronavirus. There's been widespread interest in hydroxychloroquine as both a preventative measure and for treating patients with coronavirus.
The drugs - normally used for malaria and other conditions - have been promoted and used by some world leaders, despite concerns about their safety and efficacy. President Trump has promoted it, and even took it himself for a while to ward off infection.
We've looked at what we know so far about these drugs. Early studies gave some hope, but a subsequent larger scale trial has shown it to be ineffective.
Why have these drugs gained prominence? What is hydroxychloroquine for?
US President Donald Trump revealed in May that he was taking hydroxychloroquine as a preventative measure against Covid-19, but later said he'd stopped. Hydroxychloroquine has long been used to treat malaria as well as other conditions such as lupus and arthritis.
Mr Trump has repeatedly referred to its potential. At a press conference in April, he said: "What do you have to lose? Take it." It's used to reduce fever and inflammation, and the hope has been that it can also inhibit the virus that causes Covid-19.
Following Mr Trump's comments, there was a sharp increase reported in prescriptions in the US for both hydroxychloroquine and the related drug, chloroquine. Some early studies showed that it may be able to shorten the duration of symptoms experienced by coronavirus patients, while others indicated it had no positive effect at all.
Brazilian President Jair Bolsonaro claimed in a video that "hydroxychloroquine is working in all places." This was removed by Facebook for breaching its misinformation guidelines. One of the world's largest studies - the Recovery trial run by Oxford University - has involved 11,000 patients with coronavirus in hospitals across the UK and included testing hydroxychloroquine's effectiveness against the disease, along with other potential treatments.
There's also been a global surge in demand for them. It concluded that "there is no beneficial effect of hydroxychloroquine in patients hospitalised with Covid-19" and the drug has now been pulled from the trial.
What are the concerns about safety? There are more than 200 other trials currently underway around the world.
Hydroxychloroquine is safe for treating malaria, and conditions like lupus or arthritis, but so far no clinical trials have recommended it for use against Covid-19. Why have the drugs become so controversial?
Safety fears were highlighted following an article in the Lancet medical journal in May which said the drugs could increase the risk of heart problems. Promotion by leading political figures such as President Trump has led to both hydroxychloroquine, and the related drug chloroquine, becoming the subject of widespread speculation online about their potential benefits and harmful effects.
But the Lancet has now retracted this because of issues around the data that was used for the research. This has led to high demand for the drugs and global supply shortages.
And the World Health Organization (WHO) said on 3 June it was resuming trials involving hydroxychloroquine, which it had earlier suspended over safety concerns. There's also been controversy within the scientific community.
Is there evidence they work against Covid-19? Trials around the world were temporarily derailed when a study published in The Lancet claimed the drug increased fatalities and heart problems in some patients.
At the moment, there's not a great deal of evidence to show whether or not they're effective for either prevention or treatment. The results prompted the World Health Organization (WHO) and others to halt trials over safety concerns.
There are trials in various countries on using the drugs to prevent Covid-19, sometimes involving frontline workers who are more likely to be exposed to the virus. However, the Lancet subsequently retracted the study when it was found to have serious shortcomings and the WHO has resumed its trials.
A trial is underway across Europe, Africa, Asia and South America, testing 40,000 people with either hydroxychloroquine, chloroquine or a placebo (a dummy drug used as a control in the test) to see if it's effective. Other studies have looked at using the drugs as a preventative measure against Covid-19.
In the US, various trials are taking place for a combination of drugs including chloroquine, hydroxychloroquine and an antibiotic called azithromycin, for treating patients who already have Covid-19. The Mahidol Oxford Tropical Medicine Research Unit (MORU) is conducting mass clinical trials and has enrolled 40,000 frontline workers in Europe, Africa, Asia and South America, giving participants either chloroquine, hydroxychloroquine or a placebo.
Nigeria is conducting trials, as are Morocco, Algeria and Senegal. However, Kenya suspended its trials in the wake of safety concerns. Professor Sir Nick White, who's leading the trial, said: "Most experts agree there is a much better chance of benefit in prevention than treatment."
Results that have come out from one clinical trial of hydroxychloroquine by the University of Minnesota in the US show it is not effective at preventing Covid-19. This study has however been placed on hold following the fallout from The Lancet's retracted study.
Over 800 US and Canadian health care workers and other individuals exposed to the virus were given either a placebo or the drug. There haven't yet been results from this or other ongoing randomised studies on the drugs as a preventative treatment.
No significant difference was found in the percentages of each group who got Covid-19. What are the side-effects of hydroxychloroquine?
Are any countries already using these drugs? A number of countries have authorised the hospital use of hydroxychloroquine or its use in clinical studies under the supervision of healthcare professionals.
There are countries using the drugs, usually in specific circumstances. In March the US Food and Drug Administration (FDA) granted "emergency use" authorisation for these drugs in the treatment of Covid-19 for a limited number of hospitalised cases.
In late March, the US Food and Drugs Administration (FDA) granted "emergency use" authorisation for these drugs in the treatment of Covid-19 for a limited number of hospitalised cases. But the FDA subsequently issued a warning about the risk of the drugs causing serious heart rhythm problems in coronavirus patients. The agency cautioned against using these drugs outside of a hospital setting or clinical trial.
That means that hospitals can request and use the medicines for Covid-19 treatment under certain conditions. There have also been reports of people poisoning themselves taking the drugs without medical supervision.
But on 24 April, the FDA issued a warning about the dangers of using the substances because of reports of heart rhythm problems in patients. The WHO has responded by advising people not to self-medicate and "has cautioned against physicians and medical associations recommending or administering these unproven treatments."
And France, which had authorised hospitals to prescribe the drugs for patients with Covid-19, later reversed the decision after the country's medical watchdog warned of possible side effects. France had authorised hospitals to prescribe the drugs for patients with Covid-19 but later reversed that decision after the country's medical watchdog warned of possible side effects.
However, Brazil has relaxed its restrictions to allow doctors to prescribe hydroxychloroquine to patients with mild coronavirus symptoms, not just those in a serious condition in hospital. Why have these drugs gained such prominence?
The US government has sent two million doses to Brazil for frontline workers and those receiving treatment in hospitals. There were a number of early small studies in China and France that claimed the drugs could benefit coronavirus patients.
The Indian government expanded the use of the drug as a preventative medicine - but only under medical supervision - for healthcare workers in non-coronavirus environments, and for police working in areas with high rates of Covid-19. But it was when President Trump first mentioned it at a press briefing in late-March that sparked a global surge of interest in the treatment.
And in April he said: "What do you have to lose? Take it."
Mr Trump revealed in May that he was taking hydroxychloroquine as a preventative measure against Covid-19, but later said he'd stopped.
Following the president's first comments, there was a sharp increase reported in prescriptions in the US for both hydroxychloroquine and chloroquine.
Brazilian President Jair Bolsonaro has also championed the drug, claiming in a video that "hydroxychloroquine is working in all places." This was removed by Facebook for breaching its misinformation guidelines.
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