Table 2.

Summary of the potential repurposed drugs currently in clinical trials for treatment of COVID-19.

Sr. no	Potential drug candidate	Mechanism of action/rationale	Current clinical status	On-going Clinical Trial for COVID-19 in different countries
Anti-viral drugs
1.	Baloxavir	Antiviral active against influenza viruses	FDA approved anti-viral medication for treatment of influenza A and influenza B flu in Japan and in the United States	Chinese Clinical Trial Registry: (CHiCTR2000029544), (CHiCTR2000029548)
2.	Favipiravir	Broad-spectrum antiviral drug which cause inhibition of viral RNA-dependent RNA polymerase against various viruses, including coronaviruses	Favipiravir is approved for treatment of influenza in Japan	National Clinical Trial Identifier: (NCT04336904), (NCT04349241), (NCT04336904), (NCT04346628), (NCT04310228), (NCT04319900), (NCT04303299), (NCT04333589), (NCT04336904), (NCT04345419) (NCT04351295), (NCT04349241) Chinese Clinical Trial Registration Number: (ChiCTR2000029544), (ChiCTR2000030113) (ChiCTR2000029548), (ChiCTR2000030894) (ChiCTR2000030987) Japan Clinical Trial Registration Number: (JapicCTI-205,238), (JPRN-jRCTs031190226), (JPRN-jRCTs041190120)
3.	Lopinavir Ritonavir	In-vitro activity against SARS-CoV-2 in Vero E6 cells; In-vitro activity against SARS-CoV-1 and MERS-CoV; showed protection in animal studies for treatment of MERS-CoV	Lopinavir/Ritonavir is an FDA approved antiretroviral drug of the protease inhibitor class used to treat HIV infection	National Clinical Trial Identifier: (NCT04307693), (NCT04276688), (NCT04328012)
4.	Oseltamivir	Anti-viral active against influenza viruses	Oseltamivir is an FDA approved drug used to treat and prevent influenza A and influenza B	National Clinical Trial Identifier: (NCT04303299), (NCT04261270), (NCT04255017)
5.	Remdesivir (recently approved by FDA as Orphan drug for COVID-19)	Broad-spectrum anti-viral (including coronaviruses)	Remdesivir is an antiviral drug, act as nucleotide analog, specifically an adenosine analogue, which inserts into viral RNA chains, causing their premature termination.	National Clinical Trial Identifier: (Phase III) (NCT04292899), (NCT04292730), (NCT04280705) (NCT04323761), (NCT04302766)
6.	Umifenovir	Broad-spectrum anti-viral with in-vitro activity against various viruses, including coronaviruses	Umifenovir is an antiviral treatment used for influenza infection used in Russia and China.	National Clinical Trial Identifier: (NCT04252885), (NCT04260594) Chinese Clinical Trial Registration Number: (ChiCTR200030254)
Supporting agents
7.	Anakinra	Disease modifying Anti -rheumatic Drug Recombinant human interleukin-1 (IL-1) receptor antagonist; inhibit cytokine release syndrome (CRS) symptoms or cytokine storm in severely ill patients	Anakinra is clinically approved to manage symptoms of rheumatoid arthritis	National Clinical Trial Identifier: (NCT04324021), (NCT04356366), (NCT04339712), (NCT04330638)
8.	Ascorbic acid	Antioxidant and cofactor for numerous physiologic reactions; may support host defenses against infection and protect host cells against infection induced oxidative stress	Ascorbic acid is clinically used to prevent and treat scurvy, a disease caused by a lack of vitamin C	National Clinical Trial Identifier: (NCT04264533)
9.	Combination of Azithromycin and Hydroxychloroquine	Azithromycin: Antibacterial with some in-vitro activity against some viruses (e.g., influenza A H1N1, Zika), has immunomodulatory and anti-inflammatory effects, including effects on proinflammatory cytokines Hydroxychloroquine: In-vitro activity against various viruses, including coronaviruses, has immunomodulatory activity that theoretically could contribute to an antiinflammatory response in patients with viral infections	Azithromycin is clinically used as adjunctive therapy to management of certain respiratory conditions (e.g., bronchiectasis, bronchiolitis, cystic fibrosis, COPD exacerbations, ARDS) Hydroxychloroquine is also FDA-approved to treat malaria and autoimmune conditions such as chronic discoid lupus erythematosus, systemic lupus erythematosus in adults, and rheumatoid arthritis	National Clinical Trial Identifier: (NCT04329832), (NCT04339426), (NCT04334382), (NCT04336332), (NCT04341870), (NCT04332094), (NCT04335552), (NCT04344379), (NCT04344444), (NCT04345861), (NCT04321278), (NCT04322396), (NCT04322123), (NCT04354428), (NCT04341727), (NCT04355052), (NCT04324463)
10.	Colchicine	Exerts broad antiinflammatory and immunomodulatory effects through multiple mechanisms, may combat the hyperinflammatory state of COVID-19 (e.g., cytokine storm) by suppressing proinflammatory cytokines and chemokines	Colchicine is clinically approved medication used to treat gout and Behçet's disease	National Clinical Trial Identifier: (NCT04326790), (NCT04322565), (NCT04328480), (NCT04350320), (NCT04355143)
11.	Corticosteroids	Potent anti-inflammatory and antifibrotic properties; use of corticosteroids may prevent an extended cytokine response and may accelerate resolution of pulmonary and systemic inflammation in pneumonia, may combat cytokine storm	Corticosteroid drugs are clinically used to treat rheumatoid arthritis, lupus, asthma, allergies and many other inflammatory conditions	National Clinical Trial Identifier: (NCT04327401), (NCT04344730), (NCT04348305)
12.	Nitric oxide	Selective pulmonary vasodilator; may be useful in the adjunctive treatment of acute respiratory distress syndrome (ARDS), a potential complication of COVID-19		National Clinical Trial Identifier: (NCT04306393)
13.	Ruxolitinib	Janus kinase (JAK) 1 and 2 inhibitor; 7 may potentially combat cytokine release syndrome (CRS) in severely ill patients Ability to inhibit a variety of proinflammatory cytokines, including interferon, during viral infections such as COVID-19	Ruxolitinib is a clinically approved Janus-associated kinase (JAK) inhibitor with potential antineoplastic and immunomodulating activities	National Clinical Trial Identifier: (NCT04331665), (NCT04334044), (NCT04338958) Chinese Clinical Trial Registry (ChiCTR2000029580), (ChiCTR2000030170)
14.	Sarilumab	Recombinant humanized monoclonal antibody specific for the interleukin-6 (IL-6) receptor; may potentially combat cytokine release syndrome (CRS) and pulmonary symptoms in severely ill patients	Sarilumab is an FDA approved human monoclonal antibody against the interleukin-6 receptor used for the treatment of rheumatoid arthritis.	National Clinical Trial Identifier: (NCT04357808), (NCT04315298)
15.	Sirolimus	Immunosuppressive agent (mTOR inhibitor) mTOR complex 1 (mTORC1) is involved in the replication of various viruses, including coronavirus	Sirolimus, also known as rapamycin, clinically used to coat coronary stents, prevent organ transplant rejection.	National Clinical Trial Identifier: (NCT04341675)
16.	ACE Inhibitors, Angiotensin II Receptor Blockers (ARBs)	Hypothetical benefit: ACE inhibitors or ARBs may have a protective effect against lung damage or may have paradoxical effect in terms of virus binding Hypothetical harm: Human pathogenic coronaviruses bind to their target cells through angiotensin converting enzyme 2 (ACE2)0.1, 4, 5 Expression of ACE2 may be increased in patients treated with ACE inhibitors or ARBs.1, 4, 8 Increased expression of ACE2 may potentially facilitate COVID-19 infections.1	Renin Angiotensin Aldosterone System Inhibitor, clinically approved for treatment of hypertension.	National Clinical Trial Identifier: (NCT04312009)
17.	Anticoagulants (low molecular weight heparin [LMWH], unfractionated heparin [UFH])	Current evidence indicates that patients with severe COVID-19 may develop a hypercoagulable state. Coagulation abnormalities observed in these patients include thrombotic disseminated intravascular coagulation (DIC), venous thromboembolism, elevated D-dimer levels, high fibrinogen levels, and microvascular thrombosis in the pulmonary vasculature	Heparin is clinically approved anti-coagulant.	National Clinical Trial Identifier: (NCT04345848)