The man, in his sixties, died of it. His wife has also been hospitalized, but is now safe. She explained to the media that when she heard the president officially extol the virtues of this product, she “remembered” that it was the same treatment that she used to care for their aquarium fish. She declares that she and her husband had each taken the equivalent of a teaspoon of product, that is to say a much too high dose… However, the form of chloroquine contained in the antiparasitic treatment of fish is not hydroxychloroquine, to which the health authorities currently refer.
Tiny but decisive differences
Each molecule has a very precise shape and dimensions, which give it specific physico-chemical properties and aptitudes. What is absolutely fascinating is that a very small difference between two molecules is enough to completely modify their properties.
Many enantiomers, for example – which are pairs of molecules of symmetrical structure but not superimposable because they differ in the orientation of a chemical bond – have distant odors. Take the example of the limonene molecule, which is found in the essence of various citrus fruits. In nature, it exists in two forms: one of the enantiomers smells of lemon, the other smells of orange. Likewise, fennel and dill owe their odor to one of the enantiomers of the carvone molecule; its “double” gives off a spearmint aroma. In the same way, the palette of colors which nature gives us – especially in spring – is due to a family of molecules called flavonoids. Composed of three planar cyclic structures, flavonoids are often associated with a sugar molecule. Depending on the nature of this sugar and the functional groups found on the basic “skeleton”, flavonoids appear in various colors.
The hydroxychloroquine currently tested by the medical world differs from the chloroquine molecule by the addition of a hydroxyl group (-OH), as can be seen in the illustration. This is undoubtedly what allows it to be better tolerated by the body in high doses. Chloroquine phosphate is a form of chloroquine salt.
After swallowing the product, the couple quickly fell ill. Both were dizzy and vomited; the husband also had respiratory problems, after which his wife contacted the emergency department. But once in the hospital, the man died.
The incident hardly surprised Doctor Daniel Brookes, medical director of the Banner Poison and Drug Information Center : ” Given the uncertainty around COVID-19, we understand that people are trying to find new ways to prevent or treat this virus, but self-medication is not a good solution. ”
Note that the Food and Drug Administration (FDA) has not yet approved chloroquine to treat coronavirus, and clinical trials to confirm its safety and effectiveness are just beginning. The Nigerian government has strongly advised its people not to use chloroquine for self-medication, as the risk of poisoning is far too great.
On the same subject: SARS-CoV-2: the French government authorizes the extension of clinical trials on chloroquine
An effective antimalarial
Chloroquine is a synthetic substitute for quinine, a natural alkaloid with antipyretic and antimalarial properties, extracted from cinchona, a shrub from South America. Quinine was used in Europe from the 17th century. Pharmaceutical companies quickly sought to reproduce its therapeutic effects by creating new synthetic molecules. After several clinical trials, estochine – renamed chloroquine in 1946 – developed by the German company Bayer, is recognized as an effective substitute.
Therefore, chloroquine is used as an antimalarial, both preventively and curatively; it was marketed in France in 1949. It is also used to fight against certain autoimmune diseases, such as lupus and certain rheumatoid diseases such as rheumatoid arthritis. However, this remedy must be taken with caution: the doses necessary to treat pathologies other than malaria are very close to the toxicity threshold (20 mg / kg in adults). And once the threshold is reached, the side effects are important: various organic, cardiovascular and neuromuscular disorders, which can lead to death.
This is also why the pharmaceutical industry has been slow to bring this drug to market. Therefore, it is most often used in a derivative form, hydroxychloroquine, with the same pharmacological properties, but two to three times less toxic (the toxicity threshold is 6.5 mg / kg).
Antiviral action to be confirmed
In the 1960s, scientists continued their research around chloroquine. Since then, several tests in vitro have revealed a potential antiviral action of the molecule, a new hope to fight against several diseases. HIV, flu, Chikungunya, Zika, Ebola… All the results obtained in vitro are encouraging but the trials in vivo have proven inconclusive; on the contrary, in some cases, the state of health of the individuals tested (animals or humans) has even worsened.
Chloroquine, however, remains under study today in several countries; it may be effective in treating patients with COVID-19. But the High Council of Public Health and the WHO call for caution; According to the Minister of Health, Olivier Véran, chloroquine could be administered to patients suffering from “serious forms” of COVID-19, but should not be used for “less severe” forms.
Sources: Centers for Disease Control and Prevention