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.