Should clinicians exercise caution in using chloroquine and hydroxychloroquine to treat COVID-19?

Bottom Line:

Hydroxychloroquine and chloroquine have received attention in the media as an effective treatment for COVID-19, however, a recently published study by Borba et al. in Brazil (terminated early due to excessive serious adverse events) highlights potential concerns when considering their use as treatment in COVID-19 patients.


Fihn, S.D. et al. Caution Needed on the Use of Chloroquine and Hydroxychloroquine for Coronavirus Disease 2019. JAMA Network Open (2020). DOI: 10.1001/jamanetworkopen.2020.9035

Date Published:

24 April 2020


In this JAMA Network editorial, the authors summarize current clinical trial results on hydroxychloroquine and chloroquine, two drugs which have received considerable attention in the media for its use as a potential treatment in COVID-19. In particular, they comment on a study published on the same day by Borba et al. where the researchers had to stop the study prematurely following the death of 22 of the 81 patients who received doses of chloroquine. Hydroxychloroquine and chloroquine are conventionally used to treat malaria and rheumatic diseases, and are also known to prolong the QT interval and possibly induce cardiac arrhythmias. Current evidence on the effectiveness of both drugs to treat COVID-19 in the clinical environment is scant and underpowered, but this is changing as clinical trials are starting in cities across Canada.

Summary by: Mike Ge