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- André Biernath
- BBC News Brazil in São Paulo
Credit, fake images
Hydroxychloroquine (one of the versions of chloroquine) was the subject of intense dispute during the Covid-19 pandemic. Current evidence does not support its use to treat coronavirus infection.
Despite gaining fame during the pandemic, chloroquine has been used in medicine for almost 100 years. Originally created as an anti-malaria treatment, some research conducted since the 1930s and 1940s has indicated that it also has the ability to modulate the immune system.
Over the past 70 years, it has become one of the most prescribed drugs in rheumatology, an area of medicine focused on diseases that affect joints, bones, muscles, tendons, and ligaments.
Experts often recommend chronic use of these pills in patients with systemic lupus erythematosus and rheumatoid arthritis, two diseases in which the immune system attacks areas of the body itself, such as joints, skin and kidneys.
“When we first started seeing news that chloroquine was being tested to contain the pandemic, in March 2020, we were very intrigued. After all, our experience shows us that the drug must be used for three months to take effect. How would it work so quickly in covid-19, in a matter of five days? ”Asks rheumatologist Marcelo Pinheiro, from the Federal University of São Paulo.
To remedy this and other curiosities, Pinheiro coordinated a study that had the voluntary participation of around 400 medical students and almost 10,000 volunteers distributed in 20 centers in Brazil.
The aim of the study was to verify if patients with rheumatological diseases who had been taking chloroquine for more than five years had some type of protection against coronavirus infection or if the condition would be milder and without major complications in them.
The conclusion of the work is in line with other investigations that have been carried out in recent months: the use of chloroquine has not changed the risk of suffering from covid-19 or developing the most severe forms, requiring hospitalization or intubation.
The research, anticipated first hand by BBC News Brazil, will be presented this Friday (11/20) during the Brazilian Congress of Rheumatology.
Step by step study
The work of the team of experts began at the end of March, with the inclusion of volunteers. On May 17, this stage ended with the confirmation that 9,589 people would be part of the experience.
Of these, 5,166 people had lupus, rheumatoid arthritis, or other rheumatological diseases and had been using chloroquine every day for several years.
The remaining 4,423 had no such disease and were relatives or friends of patients who lived in the same house. “We selected this control group because they share the same routine and are exposed to a similar risk of becoming infected with the coronavirus,” justifies Pinheiro.
The thousands of participants were distributed in 97 Brazilian cities and were cared for in 20 centers specialized in rheumatology.
To accompany so many people, Pinheiro created a real working group. “We have the support of the Brazilian Society of Rheumatology, of which I am a member, and we have the work of 395 medical students,” he says.
This team was in charge of calling all the volunteers every 15 days. The proposal was to find out how their health was, if they had gotten sick or had any symptoms suggestive of covid-19.
“In addition to this follow-up, we also installed a call center, where the patient could call if he was ill in the meantime of two weeks,” adds the rheumatologist.
Credit, fake images
Diseases such as rheumatoid arthritis and lupus have an autoimmune origin. This means that the immune system itself begins to attack some body structures, such as the joints. The most common symptoms include pain and swelling.
After data collection and statistical analysis, the scientists were able to compare the two groups in relation to the higher probability of developing COVID-19: patients with rheumatological diseases who used chloroquine versus people without these diseases who lived in the same residence.
The conclusion of the work was that there was no difference between the two classes. “Chloroquine did not protect or prevent serious forms, which require intubation,” Pinheiro summarizes.
Questions without answer
Despite bringing a series of novelties, the Brazilian research also has limitations. It was only presented at a conference to begin with and has yet to be reviewed by independent scientists before publication in a journal.
“We have already sent the work to some specialized magazines and we are waiting for the answer”, says Pinheiro.
Another point worth mentioning: The study did not conduct any tests to verify whether all patients who reported symptoms actually had COVID-19. “We used the clinical criteria established by the Ministry of Health, because at that time of the pandemic, resources were scarce and the orientation was to test only in the most severe cases,” explains the rheumatologist.
Therefore, it is possible that a part of the volunteers will get other respiratory diseases, such as flu or cold. However, as the circulation of Sars-CoV-2 was (and is) very intense in the country, it is very likely that most of them were affected by covid-19.
Chloroquine in rheumatic diseases
This remedy is often used in cases of systemic lupus erythematosus and, more occasionally, in rheumatoid arthritis. “It has a reasonable role as an immunomodulator, that is, it controls the inflammatory process caused by the immune system and relieves discomfort such as swelling and pain,” explains rheumatologist Rubens Bonfiglioli, professor at the Faculty of Medicine at the Pontifical Catholic University of Campinas.
In the context of these diseases, chloroquine is extremely safe and does not cause major side effects. It is even prescribed for pregnant or lactating women.
Its most worrisome adverse event occurs in vision, since the accumulation of the drug in the body over time can affect some structures of the eyeballs. “To avoid this, just make an appointment a year with an ophthalmologist,” explains Bonfiglioli, who is also the president of the Brazilian Congress of Rheumatology this year.
The doctor is sure that the promotion of chloroquine against covid-19 affected patients who really needed it.
“Before, medication was easily available and at a very affordable price. With the pandemic and all the national and international publicity that was being made, it began to disappear or have an exorbitant price in pharmacies. Our patients suffered from it ”, he reports. .
Credit, fake images
Due to increased demand, patients who really needed chloroquine (such as those affected by lupus and rheumatoid arthritis) have suffered from shortages and rising prices of the drugs in recent months.
“Only in the future will we be able to really understand what happened in this story”, analyzes infectologist Alexandre Zavascki, a professor at the Federal University of Rio Grande do Sul.
In short, it all started at the beginning of the pandemic, when scientists evaluated whether there were already drugs available on the market that could inhibit Sars-CoV-2. In laboratory experiments with cell cultures, chloroquine showed this ability.
Immediately afterwards, a group of French specialists led by the doctor Didier Raoult published a study with 36 patients suggesting that this remedy could be effective in covid-19. The work, however, presented a series of methodological flaws and generated strangeness in the academic community. “remembers Zavascki.
This information served as a trigger for world leaders, such as the American Donald Trump and the Brazilian Jair Bolsonaro, to reveal chloroquine as the solution to end the pandemic.
At the end of October, President Bolsonaro even told some supporters in front of the Planalto Palace that “in Brazil, taking chloroquine at the onset of symptoms, there is a 100% cure.”
Science, however, does not support these claims. “We already have several studies that clearly show a lack of benefit from chloroquine in the context of COVID-19. The evidence against its use is particularly strong in the most severe cases,” says Zavascki.
Even in mild cases, where some advocates speak of “early treatment,” chloroquine’s firepower is highly questionable. “First, it is extremely difficult to define what would be the early treatment, since Brazil does not even have the structure to make the rapid diagnosis. There is a delay in the development of symptoms and a wait for the results of the tests.” , highlights the infectologist.
The second point is that, in patients who develop the mildest form of covid-19, the disease usually progresses well, without the need for specific medications. Thus, whether or not an infected person with a mild condition takes chloroquine, in most cases the end result will be the same.
Zavascki realizes that, in recent months, the popularity of chloroquine has been declining in consultations. “It was common for there to be cases of people who came to us and demanded treatment with chloroquine, which was a very delicate situation. More recently, this demand has decreased a lot, ”he observes.
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