favipiravir + chloroquine phosphate

Favipiravir + chloroquine phosphate is a combination therapy that has been investigated for the treatment of COVID-19. Favipiravir is an antiviral drug that selectively inhibits RNA-dependent RNA polymerase (RdRp), preventing viral genome replication. After being converted to its active form (favipiravir-RTP), it acts as a pseudo purine that either binds to the catalytic domain of RdRp or gets misincorporated into the nascent viral RNA, causing chain termination and lethal mutagenesis. Chloroquine phosphate is an antimalarial drug that acts as a weak base, increasing endosomal pH and potentially inhibiting viral entry steps that are pH-dependent. It may also disrupt post-translational modifications of viral glycoproteins, affecting virus infectivity. This combination was studied for potential synergistic effects against SARS-CoV-2.