Umifenovir
Umifenovir is an indole-based hydrophobic dual-acting direct antiviral/host-targeting agent used for the treatment and prophylaxis of influenza and other respiratory infections. It has been in use in the treatment of influenza in China and Russia for so many years (Fink et al., 2020; Pshenichnaya et al., 2019).
It has been reported to have inhibitory effects on a diverse array of viruses, including DNA and RNA viruses (SARS-CoV-2 is an RNA virus) as well as capsid and membrane-enclosed viruses (Fink et al., 2020; Pshenichnaya et al., 2019). Umifenovir inhibits the entry of the influenza virus at the late stage by binding directly to influenza haemagglutinin (HA) and inhibiting its ability to transit to an activated conformation. It also impairs fusion by intercalation into the viral or target membrane, thereby rendering the membrane less yielding for fusion.
Major adverse effect is hypersensitivity in children. It is administered orally with an elimination half life of 17-21 hours (Fink et al., 2018; Hulseberg et al., 2019).