Hydroxychloroquine
Hydroxychloroquine (HCQ) sulfate, a derivative of Chloroquine (CQ), was
first synthesized in 1946 by inserting a hydroxyl group into CQ and was
shown to be much less (~40%) toxic than CQ in
animals[13]. More significantly, HCQ is now commonly available for
the treatment of autoimmune diseases such as systemic lupus
erythematosus and rheumatoid arthritis. Since CQ and HCQ share similar
chemical structures and mechanisms to serve as a weak base and
immune-modulator, the idea that HCQ may be a potent candidate for
treating SARS-CoV-2 infection is simple to conjure up [28]. As of 23
February 2020, seven registries of clinical trials have been listed in
the Chinese Clinical Trial Registry (http:/www.chictr.org.cn) to use HCQ
for COVID-19 diagnosis. The experimental evidence still lacks whether
HCQ is as effective as CQ in the treatment of SARS-CoV-2 infection
[29]. Hydroxychloroquine on viruses is generally the same as
chloroquine because the action mechanism of these two molecules is
similar, so researchers are more inclined to administer
hydroxychloroquine for long periods, which will therefore be the first
option in the treatment of SARS-CoV-2. Hydroxychloroquine performed
pharmacology based pharmacokinetics (PBPK) modelling to evaluate its
activity in the lung. In vitro analyses in Vero cells
demonstrated that the potency of hydroxychloroquine (EC50 of 0.72 μM)
was greater than that of Chloroquine against 2019-nCoV.