新型コロナで注目の抗マラリア薬、むしろ死亡率上げる恐れ　研究

【ワシントンＡＦＰ＝時事】新型コロナウイルス感染症（COVID-19）の特効薬になるのではないかと大きく取り沙汰されていた抗マラリア薬「ヒドロキシクロロキン」が、標準的な治療では効果がなく、むしろ死者を増やしていた恐れがあるという研究が21日、発表された。（写真は資料写真）
　ヒドロキシクロロキンを投与された米退役軍人の治療結果を調べた未査読論文がプレプリントサイトで発表された。米政府の資金で実施された研究で、この種のものとしてはこれまでで最大規模。
　ドナルド・トランプ米大統領やＦＯＸニュースなどがヒドロキシクロロキンを推していたが、この実験は、いくつかの大きな制約があったものの、ヒドロキシクロロキンの効果への疑念を増大させる結果となった。
　研究では、米国で入院し４月１１日までに死亡あるいは退院した退役軍人３６８人の医療記録を調べた。調査対象となった患者の死亡率は、ヒドロキシクロロキンのみを投与された場合は２８％、抗生物質アジスロマイシンと併せて投与された場合は２２％だった。この２剤併用は、仏地中海感染症大学病院研究所のディディエ・ラウール氏が３月に行った研究で効果があったと発表したことで世界的な注目を集めていた。
　一方、標準的な治療のみを受けた患者の死亡率は１１％だった。
　しかし、今回分析対象となったのは、主に糖尿病や心臓病などの基礎疾患がある６５歳以上の黒人男性だったため、この結果を一般化するのは難しい。
　真の答えを得るには、患者を二つのグループに分け、一方には評価しようとしている薬品を、もう一方には偽薬（プラセボ）を投与する無作為化対照臨床試験（ＲＣＴ）を大規模に行うしかない。このような臨床試験はすでに米国、欧州、カナダ、英国で始まっている。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2020/04/22-13:17）

A malaria drug widely touted as a potential cure for COVID-19 showed no benefit against the disease over standard care -- and was in fact associated with more deaths, the biggest study of its kind showed Tuesday.
The US government funded analysis of how American military veterans fared on hydroxychloroquine was posted on a medical preprint site and has not yet been peer reviewed.
The experiment had several important limitations, but adds to a growing body of doubt over the efficacy of the medicine that counts President Donald Trump and right wing news channel Fox News among its biggest backers.
Researchers looked at the medical records of 368 veterans hospitalized nationwide who either died or were discharged by April 11.
Death rates for patients on hydroxychloroquine were 28 percent, compared to 22 percent when it was taken with the anti-biotic azithromycin -- a combination favored by French scientist Didier Raoult, whose study on the subject in March triggered a surge of global interest in the drug.
The death rate for those receiving only standard care was 11 percent.
Hydroxychloroquine, with or without azithromycin, was more likely to be prescribed to patients with more severe illness, but the authors found that increased mortality persisted even after they statistically adjusted for higher rates of use.
Other drawbacks include the fact that the study did not assign people randomly to groups, because it was a retrospective analysis meaning it looked back on what had already happened.
In addition, the results are hard to generalize because the population was highly specific: most of the patients were male, with a median age over 65, and black, a group that is disproportionately affected by underlying illnesses like diabetes and heart disease.
There was no added risk of being on ventilator among the hydroxychloroquine only group, leading the authors to suggest that increased mortality among this group might be attributable to side-effects outside the respiratory system.
Previous research has found that the medicine is risky for patients with certain heart rhythm issues and can cause blackouts, seizures or at times cardiac arrest in this group.
Hydroxychloroquine and a related compound chloroquine have been used for decades to treat malaria, as well as the autoimmune disorders lupus and rheumatoid arthritis.
They have received significant attention during the novel coronavirus pandemic and have been shown in lab settings to block the virus from entering cells and prevent it replicating -- but in the pharmaceutical world, in vitro promise often fails to translate into in vivo success.
The true answer can only be determined through very large, randomized clinical trials that assign patients to receive either the drug under investigation or a placebo.
Several of these are underway, including notably in the United States, Europe, Canada and the United Kingdom.