Administered to people who have been in close contact with infected individuals, hydroxychloroquine does not prevent the appearance of COVID-19, concludes a clinical trial carried out in Canada, including at the McGill University Health Center (MUHC), as well as in the United States. The results of this study are published today in the New England Journal of Medicine.
In this clinical trial involving 821 asymptomatic young adults who had been exposed to a person with COVID-19 at home or in a healthcare setting, 414 participants received pills within four days of their exposure. hydroxychloroquine they were to take for five days, while 407 participants received placebo tablets. Both the researchers and the participants were unaware of which treatment, hydroxychloroquine or placebo, was administered.
Among the 821 participants, 719 had suffered a high-risk explosion because they had remained for more than ten minutes in the presence, more precisely within two meters, of an infected person, without any protection, that is, without wearing a mask or face shield.
Within 14 days of treatment, 49 of those who had been treated with hydroxychloroquine developed COVID-19, or 11.9% of them, and 58 of those who received placebo, or 14 , 3%. Since the absolute risk reduction does not exceed 2.4%, the study authors conclude that hydroxychloroquine is ineffective in significantly reducing the risk of developing COVID-19 in people who have been in contact with an infected person.
Dr. Emily McDonald, who co-edited the portion of the study done at McGill and is therefore co-author of the publication, notes that this is “the first clinical trial to be properly conducted, either with” controls “, that is, comparing the drug with a placebo, and where the treatment (the drug or placebo) was randomly assigned to the patients (” randomized study “), and without the experimenters and participants did not know what was administered (double blind).
Dr. McDonald also wishes to point out that the medication did not cause any serious complications, including cardiac arrhythmia or death, in any of the participants, “which eliminates our concerns about the safety of the medication in healthy people of less ”.
Director of the MUHC Clinical Practice Assessment Unit, Dr. McDonald explains that this study was undertaken because hydroxychloroquine was known for its ability to decrease replication of the virus. “After someone has been exposed to the virus, the virus must replicate [et se multiplie] in the body for the disease to appear. However, we thought that this drug could perhaps decrease the replication of the virus and thus prevent the development of the disease, or at least its symptoms, ”she said.
This clinical trial was conducted by the University of Minnesota, McGill University, the University of Manitoba and the University of Alberta.