Clinical use in COVID-19
Most antiviral agents used for COVID-19 act either by inhibiting RNA-dependent RNA polymerase (remdesivir (GS-5734)) or proteases (lopinavir/ritonavir (LPV/r), favipiravir (FPV), ribavirin and darunavir) (37-40). Additionally, umifenovir plays a role in viral entry by inhibiting the hemagglutinin-mediated membrane fusion, and oseltamivir is a neuraminidase inhibitor which blocks the release of viral particles from the host cells in influenza infection (41). Remdesivir and FPV are considered to be the most effective agents and are mostly used in combination with other COVID-19 medications like hydroxychloroquine (37-40). Oseltamivir is recommended for concomitant influenza infection (42). Darunavir or LPV/r can be concomitantly administered with chloroquine or hydroxychloroquine (40).