Paris (AFP)

Patients treated "long term" with chloroquine or hydroxychloroquine, especially for autoimmune diseases, were no less affected by severe forms of Covid-19 during the epidemic, shows a French study published Tuesday.

This study, conducted on nearly 55,000 patients, "does not suggest a preventive role for the use of synthetic antimalarials (PSA) in the long term on the risk of occurrence of hospitalization, intubation or death linked to Covid-19 ", conclude its authors.

"Even if the observational nature of the study does not formally conclude that there is no benefit from synthetic antimalarials for the prevention of a severe form of Covid-19, these results do not argue in favor of using preventive of hydroxychloroquine in the population, including the population most at risk, and this outside of dedicated therapeutic trials ", insist the researchers.

They studied "all of the people who received at least six reimbursed deliveries of synthetic antimalarials (hydroxychloroquine or chloroquine) between January 1, 2019 and February 15, 2020, the last of which during the last quarter of 2019 or early 2020" .

Hydroxychloroquine, derived from the antimalarial chloroquine, is particularly prescribed in the treatment of autoimmune diseases such as lupus and or rheumatoid arthritis.

The results even highlight "an increased risk of hospitalization, intubation and death linked to Covid-19 among patients on long-term PSA compared to the general French population".

But "the analyzes carried out suggest that this over-risk is explained by the characteristics linked to the underlying chronic pathology" of these patients, "in particular the co-medication with oral corticosteroids, rather than by the exposure to PSA itself ".

This study was carried out by Epi-flagship, a structure bringing together the Medicines Agency (ANSM) and Health Insurance, using data from the latter (in particular reimbursement of medicines) and hospital medical records (dates of hospitalization, diagnostics, medical procedures and medicines delivered ...)

Most of the clinical trials testing hydroxychloroquine were stopped in late May, after the publication of a negative study in the medical journal The Lancet (later withdrawn after suspicion of fraud), then after the results in early June of a large British trial, Recovery, that hydroxychloroquine shows "no benefit" for patients with Covid-19.

In France, the derogatory authorization to prescribe hydroxychloroquine in hospitals for the treatment of Covid-19, outside of clinical trials, was withdrawn on May 4.

© 2020 AFP