INTRODUCTION
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel
single-stranded RNA virus associated with an acute pulmonary disease
known as COVID-19. The binding between SARS-CoV-2 spike (S) protein and
human receptor cells may lead to a dysregulated immune response with
increased release of pro-inflammatory cytokines implicated in
multi-organ damage and risk of death. Given the lack of effective and
safe anti-viral agents against SARS-CoV-2, drug repurposing has played a
critical role in the identification of rapidly available therapeutic
solutions in treating patients with COVID-19 [1].
To date, only remdesivir and tocilizumab were approved by the US Food
and Drug Administration (FDA) and other healthy agencies for the
treatment of certain hospitalized patients with COVID-19. Other
promising drugs including anti-malarial agents have also been tested in
controlled clinical settings, but no benefits were found in preventing
or treating patients with SARS-CoV-2 infection [2].After a
comprehensive review by Sanders and colleagues [3] in April 2020 and
a letter to the editor published by our research group in July 2020 in
the American Journal of Physiology-Lung Cellular and Molecular
Physiology [4] calling attention for the potential anti-viral
effects of nitazoxanide and the need of high-quality trial evidence of
nitazoxanide in the treatment of SARS-CoV-2 infection, 28 interventional
studies were registered on ClinicalTrials.gov of which 8 were completed
or published by June 2021.
The best evidence synthesis to assess treatment effects can be obtained
through the identification, critical appraisal, and summary of results
from blinded, placebo-controlled, randomized clinical trials (RCT)
considered the gold standard in clinical research. The aim of this rapid
and living systematic review and meta-analysis was to synthesize the
available evidence on the efficacy and safety of nitazoxanide as a
treatment option in patients with COVID-19.