>>In vitro and preliminary clinical research have suggested that hydroxychloroquine alone and in combination with azithromycin could prove to be an effective treatment for COVID-19.

A small study in France enrolling 26 treated patients and 16 non-randomized controls showed that hydroxychloroquine alone or in combination with azithromycin shortened the time to resolution of viral shedding of COVID-19.1

Based on this study, clinicians in many countries have begun using these medications in clinical practice, and multiple randomized trials are being initiated. However, chloroquine, hydroxychloroquine and azithromycin all prolong QT interval, raising concerns about the risk of arrhythmic death from individual or concurrent use of these medications.

Both the concerns regarding mortality risk, and the intensity of QT and arrhythmia monitoring should be considered in the context of several important mitigating factors:

The duration of use for these medications for COVID-19 infection is short (5 to 10 days for acute illness).

While QT-prolonging medication use has been associated with increased risk of death, this risk may be smaller than the potential benefit from treatment of COVID-19 for some patients.

There are large potential population-health benefits from hastening viral clearance of COVID-19.

https://www.acc.org/latest-in-cardiology/articles/2020/03/27/14/00/ventricular-arrhythmia-risk-due-to-hydroxychloroquine-azithromycin-treatment-for-covid-19