1.1 Pathogenesis of COVID-19
Clinically, COVID-19 is characterized by fever, cough, myalgia and
dyspnoea, sometimes evolving into fulminant respiratory failure. Though
the pathogenic mechanisms are diverse, there are two major processes
that lead to the morbidity and mortality of this disease: initially the
viral infection, followed by a host inflammatory response that
frequently results in excessive secretion of inflammatory cytokines
(e.g. IL-2, IL-6, IL-8, IL-10 and TNFα). This immune response can
develop into a self-targeting toxic “cytokine storm” in which the
lungs fill with inflammatory secretions causing critical damage to
pulmonary tissue. Accordingly, the development of therapeutics for
COVID-19 can be divided into two groups: anti-viral and
anti-inflammatory. Even though the search for a vaccine and anti-viral
agents has already been initiated, the de novo development of a
safe, COVID-19 specific solution and its worldwide distribution may take
several years; regrettably, the need for a therapeutic that is available
immediately is growing daily. Therefore, repurposing an already approved
drug may offer a promising approach to address this urgent need.