Coronavirus disease 2019 (COVID-19) has been a major global health crisis
since the influenza pandemic of 1918. Based on data from in vitro studies, traditional
antimalarial agents, chloroquine and hydroxychloroquine, have been proposed as
potential treatment options for patients with COVID-19. Both these medications have
also been noted to prolong the QT interval, which increases the risk of drug-induced
torsade de pointes (TdP) or sudden cardiac death (SCD) when used in non-COVID-19
patients. We reviewed the published clinical studies evaluating the QT interval in
COVID-19 patients treated with chloroquine/hydroxychloroquine with or without
azithromycin. A literature search using Google Scholar, and PubMed was done for
studies published from December 2019 to September 2020. Studies with no specific
description of the QT interval were excluded from this review. We identified twelve
studies that qualified our criteria, which included 2595 patients. This review addresses
the pathophysiology of QT prolongation and the incidence of the magnitude of QT
prolongation associated with these medications when used in the treatment of patients
admitted with COVID-19. Although most incidences of QT prolongation occurred two
or more days after the initiation of these medications, early events of QT prolongation
on the first day of therapy have also been reported. Notably, the combination of
chloroquine/hydroxychloroquine with azithromycin was associated with a higher
incidence of QT prolongation. Although QT prolongation is evident in all the described
studies, none of these studies were designed to address the risk of QT prolongation
associated with these medications in the outpatient setting or when used as prophylaxis
against COVID-19. With the currently available literature, caution with close
monitoring of the QT interval is advised when using these antimalarial agents in
patients hospitalized with COVID-19 infection.
Keywords: Chloroquine, Coronavirus disease 2019, Covid-19, Drug-induced
torsade de pointes (tdp), Hydroxychloroquine, Hydroxychloroquine and
azithromycin, Qt prolongation, QTc prolongation, SARS-CoV-2, Sudden cardiac
death.
