Theory and reality of antivirals against SARS-CoV-2

Table 1 Summary of each drug used in clinical practice[8,51,64-67]

Antiviral	Notes	Usage and dosage (adults)
IFN	(1) Not recommended for the treatment of patients with severe or critical COVID-19, except in a clinical trial; (2) Patients with early (i.e., < 7 d from symptom onset) mild and moderate disease may benefit; and (3) IFN-α has primarily been used as nebulization and usually as part of a combination regimen	(1) Nebulized INF-α: 5 million units, add 2 mL of sterile water for injection, twice daily. Preferably less than 10 d; and (2) Subcutaneous IFN-β: 8 million international units every other day. Preferably less than 10 d
LPV/r	(1) Not recommended to treat patients with COVID-19 at any severity; (2) Not recommended to use alone; and (3) The plasma drug concentrations of typical doses are far below the levels that may be needed	Lopinavir 400 mg/ritonavir 100 mg orally twice daily. Preferably less than 10 d
RBV	(1) There is not enough sample size, scientific and objective clinical data to prove effective; and (2) Not recommended to use alone. Usually in combination with IFN and/or LPV/r	500 mg per time, inject 2-3 times per day intravenously. Preferably less than 10 d
CQ	(1) Not recommended to treat patients with COVID-19 at any severity; and (2) Recommendation against CQ with or without azithromycin	(1) CQ 600 mg twice daily for 10 d (high dose, serious side effect). CQ 450 mg twice daily for 1 d, then CQ 450 mg for 4 d (low dose, mild side effect); (2) HCQ 800 to 1600 mg orally on the first day, 1 to 3 divided doses. 200 to 800 mg orally daily for 5 to 21 d, 1 to 2 divided doses; and (3) CQP 500 mg twice daily for 10 d
Arbidol	There is not enough sample size, scientific and objective clinical data to prove effective	100 mg orally twice daily for 5 d. Preferably less than 10 d
Favipiravir	There is not enough sample size, scientific and objective clinical data to prove effective	1600 mg for the first dose, then 600 mg orally twice daily for 5 d
Remdesivir	(1) Remdesivir is the only Food and Drug Administration-approved drug for the treatment of COVID-19; and (2) Consider remdesivir for hospitalized patients with COVID-19 who require supplemental oxygen but who do not require oxygen delivery through a high-flow device, noninvasive ventilation, invasive mechanical ventilation, or extracorporeal membrane oxygenation	200 mg on day 1, then 100 mg injected intravenously once daily for 5-7 d
Thymosin α1	There is not enough sample size, scientific and objective clinical data to prove effective	1.6 mg subcutaneous injection, twice a week, each time 3-4 d apart. Preferably more than 4 wk

IFN: Interferon: LPV/r: Lopinavir/litonavir; RBV: Ribavirin; CQ: Chloroquine; HCQ: Hydroxychloroquine; CQP: Chloroquine phosphate; COVID-19: Coronavirus disease 2019.