What's new for chloroquine and hydroxychloroquine in the treatment of the Corona epidemic?

Experiments are underway in a number of countries for drugs derived from chloroquine and hydroxychloroquine, along with other molecules, to treat people with the emerging coronavirus (Covid-19). What do we know about these two components? What is the difference between tests, studies and uses?

What is chloroquine?
Chloroquine is a compound form of quinine extracted from eucalyptus, used for centuries to treat malaria. Chloroquine is sold under several names according to countries and laboratories, and it is known as nivakin or risokin.

As for hydroxychloroquine, it is derived from chloroquine, but it is less toxic than it. It is known in France under the name Plaquenil and is used to treat rheumatoid arthritis and lupus.

Waiting for a vaccine that does not know when it will be reached, and will certainly not be ready a year ago, scientists are testing existing drugs and mixing them, in an effort to find a treatment as soon as possible for the Covid-19 pandemic sweeping the world.

Chloroquine and hydroxychloroquine are distinguished from other molecules by the availability and known of their low price. The two drugs were known before the spread of the Covid-19 epidemic, and their antiviral properties were the subject of many studies, whether in the laboratory or on different animals and viruses.

"It has been known for a long time that chloroquine and the derivative hydroxychloroquine inactivated in vitro proliferation" some viruses, "said a researcher in microbiology who specializes in infectious diseases at the Pasteur Institute Marc Locoy.

He added that recent experiments confirmed - as expected - that the two substances "in the laboratory have an anti-viral effect" on the emerging corona virus.

But "this does not necessarily assume that these two drugs have antiviral action in the body of the human being," citing in this regard several "disappointing" experiences on dengue virus, as they had no effect, and on Chikungunya fever, where this "helped" The molecules are actually on the growing virus.

Scientific controversy
Three studies - one Chinese and two French - revealed positive results in patients with the emerging coronavirus. Chinese experiments included 134 people in different hospitals, and concluded that chloroquine had a positive effect.

In France, Professor Didier Raoul is experimenting with hydroxychloroquine. After a first study of twenty patients, a second study was published on Friday evening, which this time conducted on eighty patients, all of whom received a treatment that includes a mixture of hydroxychloroquine and azithromycin, a well-known antibiotic used to eliminate secondary bacterial infections.

"We confirm the efficacy of the use of hydroxychloroquine in conjunction with azithromycin in the treatment of Covid-19," he wrote with his team from the university hospital institute "Mediterane Infinixion" in Marseille.

However, many scientists - joined by the World Health Organization - stressed the limits of these studies, as they were conducted without taking into account the usual scientific principles followed, such as choosing patients by lottery, and conducting experiments without the participants or doctors knowing who is actually receiving treatment, and the results are published In a scientific journal with an independent review committee, and others.

In evidence of the complexity of the topic, another Chinese clinical study, the results of which were published March 6, did not conclude a special drug efficacy for thirty patients.

"There is no study that proves anything in relation to the efficacy of living organisms," said Christoph Danver, the science director of the "Pasteur Institute".

"These questions do not imply that hydroxychloroquine is of no use in the treatment of Covid-19," Mark Lowqui explained. "Rather, in order to know this, it should be scientifically evaluated using a clinical trial approach."

Risks
And warns a section of the scientific community and health authorities against the rapid adoption of these properties. "One of these uncalculated consequences could be the loss of chloroquine, while people need it to treat rheumatoid arthritis, for example," Peter Bates, a former official at the US Food and Drug Administration, told AFP.

Also, there are many side effects, from nausea, vomiting, and rash, to eye diseases, cardiac and nervous disorders ... and, accordingly, excessive intake of the drug may be dangerous, and may even be fatal.

However, the publicity surrounding this substance may compel people to take it on their own without consulting a doctor. An American died this week after consuming a type of chloroquine found in a substance used to clean aquariums. Two Nigerians were also transferred to the hospital's emergency department after taking large amounts of the anti-malarial drug.

"There is an emphasis on the hope that these drugs will be effective in treating (patients), without a logical margin that dictates taking into account the possible side effects of these powerful drugs," said American heart doctor Michael Ackerman.

Who uses it against Corona?
In the light of the current emergency health situation, some doctors, some countries and some officials call for prescribing hydroxychloroquine in patients.

US President Donald Trump showed enthusiasm, describing the drug as a "godsend", while Greece has reactivated its production, and Morocco is considering using it to treat "confirmed infections."

Given the increasing demand for chloroquine and hydroxychloroquine a few weeks ago, we can assume that some doctors around the world have prescribed it against the Covid-19 epidemic.

Didier Raoul publicly pledged to distribute hydroxychloroquine with azithromycin to "all patients" with the virus.

But there are voices in the scientific community and some health organizations that call for a wait until the results are proven according to the pure scientific approach.

Other experiences
A European experiment called "Discovery" began with the testing of four treatments, including hydroxychloroquine, on 3,200 patients in several countries, including eight hundred in a serious condition in France.

In the United States, a large-scale clinical trial began on Tuesday in New York, the epicenter of the epidemic in that country, under the supervision of the Food and Drug Agency, and the World Health Organization has launched a massive international clinical trial.

While awaiting the results, some countries are taking a cautious stance, and France has allowed the use of hydroxychloroquine, as well as anti-viral drug leponavir and ritonavir, but only in hospital and only in serious cases.

The French National Council of Physicians announced on Friday that "doctors must act as professionals with a sense of responsibility, and are awaiting confirmation or denial of the effectiveness of this treatment."

He continued, "The worst thing that our citizens can face is the feeling of disappointment or seeing a treatment that the first evidence proved to be effective, but it is no longer available for prescribing or distribution due to its uncontrolled use."