Table 2.
Existing drugs with therapeutic potentials for COVID-19 (drug repurposing) [99]
| Drug candidate | CAS RN | Target | Possible mechanism of action on COVID-19 | Disease indication |
|---|---|---|---|---|
| Baricitinib (C16H17N7O2S) [106] | 1187594-09-7 | JAK kinase | A JAK inhibitor that may interfere with the inflammatory processes | Approved drug for rheumatoid arthritis |
| Lopinavir (C37H48N4O5) [89a] | 192725-17-0 | Viral proteases: 3CLpro or PLpro | Protease inhibitors that may inhibit the viral proteases: 3CLpro or PLpro | Lopinavir and ritonavir are approved drug combination for HIV infection |
| Ritonavir (C37H48N6O5S2) [89a, 110c] | 155213-67-5 | |||
| Darunavir (C27H37N3O7S) [105] | 206361-99-1 | Approved drug for HIV infection | ||
| Favipiravir (Favilavir) (C5H4FN3O2) [100, 109] | 259793-96-9 | RdRp | A purine nucleoside that acts as an alternate substrate leading to inaccurate viral RNA synthesis | Viral infections |
| Remdesivir (C27H35N6O8P) [89a, 98, 103a] | 1809249-37-3 | A nucleotide analogue that may block viral nucleotide synthesis to stop viral replication | Ebola virus infection | |
| Ribavirin (C8H12N4O5) [28, 100–102] | 36791-04-5 | RSV infection, hepatitis C, some viral haemorrhagic fevers | ||
| Galidesivir (C11H15N5O3) [105b] | 249503-25-1 | Hepatitis C, Ebola virus, Marburg virus | ||
| BCX-4430 (salt form of galidesivir) [105b] | 222631-44-9 | Hepatitis C, Ebola virus, Marburg virus | ||
| Arbidol (C22H25BrN2O3S) [92, 104a] | 131707-23-8 | S protein/ACE2d | An inhibitor that may disrupt the binding of viral envelope protein to host cells and prevent viral entry to the target cell | Influenza antiviral drug |
| Chloroquine (C18H26ClN3) [99, 103] | 54-05-7 | Endosome/ACE2 | A drug that can elevate endosomal pH and interfere with ACE2 glycosylation | Malarial parasite infection |
| Nitazoxanide (C12H9N3O5S) [100] | 55981-09-4 | N/A | A drug that may inhibit viral protein expression | Various helminthic, protozoal and viral infection-caused diarrheea |
Reprinted from Ref. [99]; copyright American Chemical Society, 2020
aDrugs under clinical trials for treating COVID-19 (repurposing)
bDrugs under clinical trials for other virus-induced diseases
cRitonavir is a pharmacokinetic profile enhancer that may potentiate the effects of other protease inhibitors due to its ability to attenuate the degradation of those drugs by the liver enzyme CYP3A4 and thus is used in combination with antiviral lopinavir [109]. An inhibitor of viral entry to host cells. Its direct action on S protein and ACE2 is yet to be confirmed. The molecular formulae of the drugs have been provided in the parentheses below their chemical names