Background: The COVID-19 causing coronavirus is an enveloped RNA virus that utilizes an enzyme RNA dependent RNA polymerase for its replication. Favipiravir (FVP) triphosphate, a purine nucleoside analog, inhibits that enzyme. We have conducted this systematic review and meta-analysis on efficacy and safety of the drug FVP as a treatment for COVID-19.
Methods: Databases like Pubmed, Pubmed Central, Scopus, Embase, Google Scholar, preprint sites, and clinicaltirals.gov were searched. The studies with the standard of care (SOC) and FVP as a treatment drug were considered as the treatment group and the SOC with other antivirals and supportive care as the control group. Quantitative synthesis was done using RevMan 5.4. Clinical improvement, negative conversion of reverse transcription-polymerase chain reaction (RT-PCR), adverse effects, and oxygen requirements were studied.
Results: We identified a total of 1798 studies after searching the electronic databases. Nine in the qualitative studies and four studies in the quantitative synthesis met the criteria. There was a significant clinical improvement in the FVP group on the 14th day compared to the control group (RR 1.29, 1.08-1.54). Clinical deterioration rates were less likely in the FVP group though statistically not significant (OR 0.59, 95% CI 0.30-1.14) at the endpoint of study (7-15 days). The meta-analysis showed no significant differences between the two groups on viral clearance (day 14: RR 1.06, 95% CI 0.84-1.33), non-invasive ventilation or oxygen requirement (OR 0.76, 95% CI 0.42-1.39), and adverse effects (OR 0.69, 0.13-3.57). There are 31 randomized controlled trials (RCTs) registered in different parts of the world focusing FVP for COVID-19 treatment.
Conclusion: There is a significant clinical and radiological improvement following treatment with FVP in comparison to the standard of care with no significant differences on viral clearance, oxygen support requirement and side effect profiles.
Keywords: Antiviral agents; COVID-19; COVID-19 drug treatment; Favipiravir; Severe acute respiratory syndrome coronavirus-2.