Medications have positive results in research for the treatment of coronavirus; here are 4 possibilities

Medicine used against malaria for almost 100 years and others without approval in Brazil are among the most promising after tests.

Hospital in Wuhan, where the pandemic started: patients undergoing tests with the drug showed lung improvement (photo: AFP / STR)

Four drugs showed positive - but still preliminary - results in scientific research in the treatment of Covid-19, a disease caused by the new coronavirus. These drugs act at different stages of cell contamination. They are:

  1. Chloroquine
  2. Remind
  3. Lopinavir/Ritonavir
  4. Favipiravir
However, self-medication is not recommended, since research has not been fully completed and it is not yet known whether there are any side effects from use by patients infected with the coronavirus.

The study on Favipiravir was released on Wednesday (18) - it is sold commercially in Japan under the name Avigan. It was developed by Toyama Chemical, of the Fujifilm group, and has been used for over 5 years against Influenza. Its use is only authorized in Japan.

The medicine is being tested only in laboratories outside the country. When consulted, Anvisa informed that there is no request for registration or even clinical research involving the product in Brazil.

Remdesivir also has no use approved worldwide, and is still in the phase of clinical trials. Chloroquine and Lopinavir/Ritonavir, on the other hand, are medicines with already consolidated use in the market, including in Brazil, but intended for the treatment of other diseases.

According to Donald Trump, the American president ordered the FDA to speed up the approval process of potential therapies that have an effect against Covid-19 and cited Remdesivir and Chloroquine.

Historical illustration created by the United States government promotes the treatment of malaria using chloroquine as a preventive method - Photo: CDC.
Historical illustration created by the United States government promotes the treatment of malaria using chloroquine as a preventive method - Photo: CDC.

Drugs currently being tested:

Favipiravir is an inhibitor of RNA polymerase enzyme, which is responsible for RNA synthesis and can replicate the genome of viruses such as coronavirus within cells. Favipiravir does not let the genetic material of the virus reproduce.

Chinese medical authorities announced that the medicine was effective against the disease and had no side effects. People who had the virus had a negative result - the microorganism was no longer detected - after four days of using favipiravir. Patients treated with the drug also showed an improvement in lung function.

Chloroquine has been used to treat malaria since the 1930s. It has also been used to treat autoimmune diseases such as lupus and rheumatoid arthritis.

The drug has undergone laboratory tests and prevented the virus from entering the cells, as well as preventing the spread of infected cells. A study published by Nature showed that chloroquine blocks virus infection because it changes the pH of structures needed for the virus to enter the cell.

"Chloroquine makes the pH of the inner vesicles of cells more alkaline. Studies indicate that alkalinizing these vesicles impacts the multiplication of the virus inside the cells. By drastically modifying the interior of the cells, it messes with various receptors that the virus uses to modify itself," explained Claudio Marinho, an immunologist with the USP Institute of Biomedical Sciences.

The anti-inflammatory action of the drug can also be effective against the virus. "Chloroquine decreases the inflammatory response our body uses to destroy the virus," said Marcelo Burattini, professor of tropical medicine at the Federal University of São Paulo (Unifesp).

Remdesivir is a medicine that acts by avoiding the synthesis of RNA (genetic material) of the virus in cells.

The American pharmacist Gilead holds the patent for the use of Remdesivir. Its clinical trials began in 2015 for a number of viruses, including malaria and influenza, but it is not an approved drug for use.

Gilead offered the drug for testing on a small group of patients in collaboration with the Chinese authorities and the results were promising, but they are still very preliminary.

Remdesivir has already been used twice: in 2016 and in 2018, during Ebola outbreaks. It has been approved for testing in the United States, but there are still no conclusive results, made with a large sample of patients.

Lopinavir and Ritonavir
It's one of the components of antiviral cocktails. It was used in Brazil in the 1980s and 1990s to treat HIV. It was very popular in Brazil, but it was abandoned because drugs from new generations have emerged that are more effective and have fewer side effects.

Lopinavir prevents the formation of Protease, the enzyme responsible for protein breakdown. Ritonavir, on the other hand, is a complementary remedy that prevents Lopinavir from being destroyed by the liver.

The protease inhibitor breaks large protein chains into small pieces. This is important to prevent the final assembly of the virus in the cell, because the virus inserts itself in our cellular genome and starts to command the cell, its genome uses our cellular material to make copies of itself.

The protease inhibitor prevents the virus from having its chain broken and the proteins restructured into new viruses. Compared to other drugs, Lopinavir acts at a later stage of infection.

The inhibitors have the potential to cause reasonably important adverse effects because they interfere with cellular functions, even if very specific. The compound can cause liver toxicity, gastrointestinal intolerance, nausea and vomiting.

Structure of the coronavirus, which gets its name because of the spikes in its membranes that resemble a crown.