Abstract:
COVID-19 has caused a devastating pandemic,
infecting 3,090,445 people and causing 217,769
deaths, as of 30 April, 2020. The current evidence
base for selected drugs repositioned to treat COVID19 are summarized here. Chloroquine (CQ) and
hydroxychloroquine (HCQ) block the entry of the
SARS-CoV-2 virus into cells and have immunomodulatory effects. Early, poor quality studies
pointed to benefit with CQ and HCQ treatment in
COVID-19 infection, but no further evidence supporting their use is available to date, and the drugs
cannot be recommended for treatment or prophylaxis. However, several countries use CQ or HCQ
for compassionate treatment. Lopinavir-ritonavir,
which is effective against HIV, was evaluated in one
clinical trial which showed no benefit. Remdesivir, a
drug developed for EBOLA, has been shown to have
in-vitro efficacy against SARS-CoV-2, and the treatment has been used on compassionate grounds in
severe cases. Limited studies have shown clinical
improvement with remdesivir which is approved for
emergency use in severe COVID-19. The RNA
polymerase inhibitor favipiravir has been shown to
improve clinical features, hasten viral clearance, and
improve HRCT findings. Corticosteroids have shown
no benefit. Trials are underway with the IL-6 receptor
blocking monoclonal antibody tocilizumab, with
retrospective data showing reduction in inflammatory markers and clinical improvement. Convalescent plasma has been shown to be of some
benefit in severe cases of SARS, MERS and H1N1
influenza, and is recommended by the FDA for those
with serious or immediately life-threatening infection
with COVID-19. Several large randomized controlled
trials are underway, evaluating these repositioned
therapies as well as many other treatments. No
effective specific treatments are available for COVID19 infection as yet
