In a meta-analysis of data from several studies from the beginning of the corona pandemic in 2020, scientists state a possible link to the increased mortality of covid patients treated with hydroxychloroquine and warn against hasty repurposing of drugs.
"The main objective of our study was to estimate the mortality attributable to the use of hydroxychloroquine for the treatment of Covid-19, in the first wave of the pandemic, before the publication of reliable studies," write the authors of the study, titled "Estimation of the (number of) deaths caused by the use of hydroxychloroquine during the first wave Kovida-19", published in the professional journal "Biomedicine and Pharmacotherapy".
French-Canadian researchers say hydroxychloroquine can be linked to nearly 17.000 deaths — or an 11% higher death rate in hospitalized patients.
Warning for the management of future pandemics, the authors of the study point out: "Although our estimates are limited by imprecision, these findings illustrate the danger of repurposing drugs when there is too little evidence."
We will return to this and other scientific studies, but first let us remind...
The first wave of corona - panic
During the first wave of the coronavirus pandemic, at the beginning of 2020, there was a great panic - to find cures for Kovid-19, a new disease that threatened to completely overload the health systems in large parts of the world.
And as is standard practice, while we waited for a vaccine and the development of new drugs, help was sought among already existing drugs.
One of them was hydroxychloroquine - an old, tried and tested and very cheap drug that is used in the prevention and treatment of tropical malaria, as well as for the treatment of some autoimmune diseases, for example arthritis and lupus - by reducing inflammation and pain. Most people do not experience any unwanted side effects of hydroxychloroquine, sometimes causing nausea or diarrhea or after prolonged use - damage to the eyes. When it comes to malaria, it is taken for a few weeks, but with Lupus it has to be taken for life.
Hydroxychloroquine was approved for use in the US as early as 1955. Its predecessor, chloroquine, is even older: it was developed in Germany in 1934 in search of a synthetic drug with the effects of quinine - which has been used in the folk medicine of the South American people for centuries.
Hydroxychloroquine or chloroquine are on the list of essential medicines of the World Health Organization (WHO), which are considered to be the most effective and safest for meeting the most important needs in the health system.
High hopes for hydroxychloroquine - Trump, WHO and almost the whole world
In early March 2020, then US President Donald Trump ordered the Food and Drug Administration (FDA) to test certain drugs to see if they have the potential to treat Covid-19. Among them were chloroquine and hydroxychloroquine.
In the same month, the FDA issued emergency approval for chloroquine and hydroxychloroquine - for the treatment of Covid in hospitals and clinical trials of the drugs.
Shortly thereafter, in early April, the White House lifted those FDA restrictions and ordered 23 million hydroxychloroquine tablets from the Strategic National Drug Stockpile to be distributed to dozens of US states, not only to hospitals but also to pharmacies. Trump used to say, "What have you got to lose? Take it," and later said he was taking it himself as a precaution.
Trump was not the only one. Many other world leaders also had high hopes for this drug, which was believed to be very effective, but only when taken in the early stages of Covid. Millions of people bought it just in case. Sales of this inexpensive drug have skyrocketed worldwide.
And the World Health Organization then saw hydroxychloroquine as a potential cure for Covid, said former WHO chief scientist Sumiya Swaminathan.
Many countries, such as India, have recommended to their health workers to take it daily - preventively.
"Hydroxychloroquine reduces the immune response. That's why it was originally given early in the course of Covid-19, to suppress the cytokine storm," said Subarna Goswami, a public health specialist from India.
Namely, it was discovered that Covid causes so-called cytokine storms in patients - an excessive reaction of the immune system to the infection with the coronavirus, that is, a very strong inflammation in the body, which for many ended fatally.
How one (un)scientific study changed everything
At that time, when even laymen were following scientific research, in "Lancet", one of the oldest and most respected scientific journals in the field of medicine, on May 22, 2020, a study was published that destroyed the hope for hydroxychloroquine.
In the study, allegedly based on data analysis of as many as 96.000 hospitalized patients due to Covid-19, of which 15 received hydroxychloroquine or chloroquine, with or without antibiotics, higher mortality and a higher likelihood of cardiac arrhythmias were found in those treated with hydroxychloroquine or chloroquine.
The publication of those results immediately halted trials of hydroxychloroquine as a treatment for Covid - which were being carried out around the world.
On June 15, 2020, the FDA revoked its emergency approval for hydroxychloroquine because available evidence showed "no reduction in the likelihood of death or acceleration of recovery" in patients with Covid.
And the WHO stopped its tests of hydroxychloroquine as a drug against Covid-19.
The fact that the Lancet withdrew the study already on June 5, only two weeks after its publication, due to well-founded doubts about the veracity of the data and analysis, and that it apologized - did not change anything. Nor the fact that it turned out that the authors of the study were financed by many pharmaceutical global players.
How did hydroxychloroquine affect patients with Covid?
It is difficult to say exactly how hydroxychloroquine affected patients with Covid.
The lack of large-scale studies in the first wave of the pandemic makes it difficult to determine the precise cause of death and cardiac arrhythmia. Scientists say that - they don't know - whether it was just hydroxychloroquine, something else or a combination of factors.
"The WHO trials did not show clinical improvements in patients, so we recommended that it not be used during the pandemic. We did not see any association with increased mortality then because our sample numbers were relatively small. Large amounts of data are needed to see this," said Swaminathan when asked by Deutsche Welle (DW) about the new French-Canadian study from the beginning of our article.
That study linking hydroxychloroquine to 17.000 deaths is actually a meta-analysis, a systematic review of 44 studies conducted from March to May 2020 in six countries: USA (20), Italy (12), Spain (6), Turkey (3) France (2) and Belgium (1).
Meta-analyses can be more reliable than individual studies because they combine results from many different studies, so there is more data.
But it also means that data from studies that may have used different or even conflicting methods have been combined. If the studies were adjusted - due to differences in their methodology - they could even give completely different results, comments Dr. Lars Hemkens, whose scientific paper is one of 44 reviewed for this research.
Therefore, there is still no scientific consensus on whether hydroxychloroquine contributed to the higher mortality of those suffering from Kovid-19.
This text was originally published in part in English.
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