美国明尼苏达大学David R. Boulware团队分析了羟氯喹在Covid-19暴露后的预防效果。2020年6月3日出版的《新英格兰医学杂志》发表了这项成果。

SARS-CoV-2暴露后很容易发生Covid-19。对于暴露的人，护理标准是观察和隔离。但暴露于SARS-CoV-2后，羟氯喹是否能预防症状性感染尚不明确。

研究组在美国和加拿大部分地区进行了一项随机、双盲、安慰剂对照试验，测试羟氯喹暴露后预防的效果。研究组招募了821名无症状的成年参与者，他们曾与Covid-19确诊患者进行过家庭或职业接触，少于6英尺距离，且接触超过10分钟，其中719名在接触时没有戴口罩或护目镜（高风险），102名接触时戴了口罩，但没带护目镜（中风险）。

在暴露后4天内，研究组将这些参与者随机分组，其中414例接受羟氯喹进行预防，407名接受安慰剂。最终羟氯喹组新发Covid-19发生率为11.8%，安慰剂组为14.3%，差异无统计学意义。羟氯喹组的副作用发生率为40.1%，显著高于安慰剂组（16.8%），但两组均未发生严重不良反应。

总之，在Covid-19高危或中危暴露后4天内接受羟氯喹治疗并不能有效预防感染，且毒副作用较大。

附：英文原文

Title: A Randomized Trial of Hydroxychloroquine as Postexposure Prophylaxis for Covid-19

Author: David R. Boulware, M.D., M.P.H.,, Matthew F. Pullen, M.D.,, Ananta S. Bangdiwala, M.S.,, Katelyn A. Pastick, B.Sc.,, Sarah M. Lofgren, M.D.,, Elizabeth C. Okafor, B.Sc.,, Caleb P. Skipper, M.D.,, Alanna A. Nascene, B.A.,, Melanie R. Nicol, Pharm.D., Ph.D.,, Mahsa Abassi, D.O., M.P.H.,, Nicole W. Engen, M.S.,, Matthew P. Cheng, M.D.,, Derek LaBar, Pharm.D.,, Sylvain A. Lother, M.D.,, Lauren J. MacKenzie, M.D., M.P.H.,, Glen Drobot, M.D.,, Nicole Marten, R.N.,, Ryan Zarychanski, M.D.,, Lauren E. Kelly, Ph.D.,, Ilan S. Schwartz, M.D., Ph.D.,, Emily G. McDonald, M.D.,, Radha Rajasingham, M.D.,, Todd C. Lee, M.D., M.P.H.,, and Kathy H. Hullsiek, Ph.D.

Issue&Volume: 2020-06-03

Abstract: BACKGROUND

Coronavirus disease 2019 (Covid-19) occurs after exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For persons who are exposed, the standard of care is observation and quarantine. Whether hydroxychloroquine can prevent symptomatic infection after SARS-CoV-2 exposure is unknown.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial across the United States and parts of Canada testing hydroxychloroquine as postexposure prophylaxis. We enrolled adults who had household or occupational exposure to someone with confirmed Covid-19 at a distance of less than 6 ft for more than 10 minutes while wearing neither a face mask nor an eye shield (high-risk exposure) or while wearing a face mask but no eye shield (moderate-risk exposure). Within 4 days after exposure, we randomly assigned participants to receive either placebo or hydroxychloroquine (800 mg once, followed by 600 mg in 6 to 8 hours, then 600 mg daily for 4 additional days). The primary outcome was the incidence of either laboratory-confirmed Covid-19 or illness compatible with Covid-19 within 14 days.

RESULTS

We enrolled 821 asymptomatic participants. Overall, 87.6% of the participants (719 of 821) reported a high-risk exposure to a confirmed Covid-19 contact. The incidence of new illness compatible with Covid-19 did not differ significantly between participants receiving hydroxychloroquine (49 of 414 [11.8%]) and those receiving placebo (58 of 407 [14.3%]); the absolute difference was 2.4 percentage points (95% confidence interval, 7.0 to 2.2; P=0.35). Side effects were more common with hydroxychloroquine than with placebo (40.1% vs. 16.8%), but no serious adverse reactions were reported.

CONCLUSIONS

After high-risk or moderate-risk exposure to Covid-19, hydroxychloroquine did not prevent illness compatible with Covid-19 or confirmed infection when used as postexposure prophylaxis within 4 days after exposure.

DOI: 10.1056/NEJMoa2016638

Source: https://www.nejm.org/doi/full/10.1056/NEJMoa2016638