Table 2.

In vitro activity of promising candidates for drug repositioning against COVID-19 (SARS-CoV-2)

Reference	Drug	Clinical indication	Antiviral activity		Cytotoxicity (CC50; μM)
			MOI	EC50 (μM)
Wang et al., 2020 [18]	Remdesivir	Antiviral (Ebola)	0.05	0.77	> 100
	Ribavirin	Antiviral (hepatitis C)	0.02	109.50	> 400
	Penciclovir	Antiherpetic	0.2	95.96	> 400
	Nitazoxanide	Antiprotozoal agent	0.8	2.12	> 35.5
	Nafamostat	Anticoagulant	0.01	22.50	> 100
	Favipiravir	Antiviral (RNA virus)	0.02	95.96	> 400
	Chloroquine	Anti-malarial	0.01	1.13	> 100
Liu et al., 2020 [19]	Chloroquine	Anti-malarial	0.01	2.71	273.20
	Hydroxychloroquine	Anti-malarial	0.01	4.51	249.50

MOI, multiplicity of infection; EC50, concentration of drug required to inhibit 50% of viruses; CC50, concentration of drug required to kill 50% of mammalian cells

All studies employed Vero E6 cells