3 Not Recommended
Chloroquine and Hydroxychloroquine are potent anti-malarials
with well recognized antiviral properties. These were initially
recommended because of positive outcomes in various clinical trials. In
a study conducted in the Guangdong and Hubei provinces, 197 COVID-19
patients who received Chloroquine had a shorter duration of fever and
time to undetectable RNA levels. Hydroxychloroquine used with
Azithromycin (HQ/AZ) also showed a rapid reduction in viral load of the
COVID-19 patients, compared to controls. This can be attributed to the
fact that these drugs are able to prevent the acidification of endosomes
and cause the glycosylation of the SARS-CoV-2 cellular receptor
preventing infection 3031.
However, their potential lethal side effects have called for caution.
The FDA has not recommended the high dose use of Chloroquine and has
withdrawn permission for either of these two drugs to be used in
emergency situations as of June 15th. They are only allowed in the
context of a clinical trial. The European Medicine Agency has also only
allowed the use of these drugs in the context of clinical trials or for
chronic conditions. High dose Chloroquine (600mg twice daily for ten
days) compared to low dose Chloroquine (450mg for five days twice only
on the first day) has been associated with a higher mortality rate, QT
prolongation and ventricular tachycardia 32. QT
prolongation interval is also a potential risk of HQ/AZ combination
especially in patients with pre-existing cardiac disease3334. In another study cardiac arrest was more common
in patients receiving this combination than patients who received
neither drug 35.