Ritonavir (ABT 538) is a peptidomimetic agent that inhibits both HIV-1 and HIV-2 proteases. Ritonavir is highly inhibited by serum proteins but boosts the effect of other HIV proteases by blocking their degradation by cytochrome P450.

EIDD-1931 (Beta-d-N4-hydroxycytidine) is a ribonucleoside analog with antiviral activity that inhibits the replication of severe acute respiratory syndrome coronavirus [SARS-CoV] in Vero 76 cells, Middle East respiratory syndrome coronavirus [MERS-CoV] in Calu-3 2B4 cells, and SARS-CoV-2 in Vero cells (IC50s = 0.1, 0.15, and 0.3 μM, respectively).

Umifenovir hydrochloride (Arbidol HCl) , an broad-spectrum antiviral chemical agent, can inhibit cell invade of enveloped viruses by blocking viral fusion with host cell membrane.

PF-07321332 is a potent and orally active inhibitor of SARS-CoV 3C-like protease (3CLPRO) .

Roflumilast (APTA 2217) is an orally available, long-acting inhibitor of phosphodiesterase (PDE) type 4 (PDE4), with anti-inflammatory and potential antineoplastic activities. Upon administration, roflumilast and its active metabolite roflumilast N-oxide selectively and competitively bind to and inhibit PDE4, which leads to an increase of both intracellular levels of cyclic-3', 5'-adenosine monophosphate (cAMP) and cAMP-mediated signaling.

Favipiravir (T-705) (T-705), an effective and selective RNA-dependent RNA polymerase inhibitor, are applied to treat influenza virus infections.

Imatinib (STI571) is a multi-targeted receptor tyrosine kinase inhibitor that selectively inhibits the kinase activities of BCR/ABL, v-Abl, PDGFR, and c-kit with oral activity. Imatinib has antitumor activity for the treatment of chronic granulocytic leukemia.