A randomized controlled trial by Solaymani-Dodaran et al. reported that patients with COVID-19 who were randomized to favipiravir had no significant difference in terms of mortality rate, compared to their counterparts who were randomized to lopinavir/ritonavir (favipiravir group: 13.7% versus lopinavir/ritonavir group: 11.5%). However, there have been few trials reporting the association between the use of favipiravir and the risk of mortality in patients with COVID-19, a study thus summarized the overall evidence relating the same.

Six randomized controlled trials with a total of 1669 patients with COVID-19 were included. 

The meta-analysis of the included trials indicated no significant difference in the odds of mortality with the use of favipiravir among patients with COVID-19, relative to non-use of favipiravir.

The absence of mortality benefits with the use of favipiravir in patients with COVID-19 may be due to the low plasma concentrations as favipiravir has a complex pharmacokinetic profile. 

Recently, it has been reported that combined treatment of favipiravir and molnupiravir resulted in increased antiviral efficacy in a SARS-CoV-2 hamster infection model. 

Therefore, future trials are warranted to determine the clinical efficacy of such combination rather than favipiravir alone. Along with potentially increased efficacy, such a combination also allows administration of lower doses of both agents, which can be cost-saving since molnupiravir is relatively expensive. Besides, it will also make the safety profile more favorable.

SOURCE- Int Immunopharmacol. 2022;103:108455. doi:10.1016/j.intimp.2021.108455