Table 2.

Comparative analysis of clinical trials results for drugs repurposed for the treatment of COVID-19

Drug	Mechanism of action	Clinical trial	Community	No. of treated Patients	% Patients recovered/ improved	% Patients unaffected	% Patients deceased	Adverse effects in clinical trial	Notes	Refs
Remdesivir	Adenosine analog: inhibits RNA-dependent RNA Pol	Remdesivir administration (unspecified dose) on day 7 of hospitalization	USA	1	100	–	–	No obvious adverse effects	–	[37]
		10-day treatment: Day 1: 200 mg i.v.; Days 2–10: 100 mg i.v.	USA, Japan, Italy, Austria, France, Germany, The Netherlands, Spain, Canada	USA: 22; Japan: 9; Italy: 12; Austria: 1; France: 4; Germany: 2; The Netherlands: 1; Spain: 1; Canada: 1 (total: 53)	47	68	13	Common: increased hepatic enzymes, diarrhea, rash, renal impairment, hypotension. Serious: organ-dysfunction syndrome, septic shock, acute kidney injury, hypotension	Initial number of patients was 61 but data from 8 patients not analyzed	[38]
HCQ	Increases pH of endosomes, inhibiting viral entry; binds ACE2 receptor preventing binding to SARS-CoV-2 spike	Trial no: ChiCTR2000029559; 200 mg HCQ twice daily orally	Wuhan, China	31	80.7	12.9	$–$	No severe adverse effects; mild adverse effects included rash and headache	6.5% of patients reported exacerbated symptoms	[51]
HCQ with azithromycin	Azithromycin (antibiotic)	Trial no: 2020-000890-25; all patients received 200 mg HCQ, three times daily for 10 days; 6 of these patients received azithromycin 500 mg on Day 1 and 250 mg, once daily for next 4 days	France	20 (14 patients treated with HCQ only, whereas 6 treated with both drugs)	100	0	0	No severe adverse effects	One patient died and 3 were transferred to ICU; however, these patients were not included in analysis	[112]
Favipiravir	Adenosine analog: Inhibits RNA-dependent RNA Pol	Trial no: ChiCTR2000029600; 1600 mg favipiravir twice daily on Day 1; 600 mg Favipiravir twice daily from Day 2 to Day 14	Shenzhen, China	35	91.43	6.45	$-$	No severe adverse effects; mild adverse effects included diarrhea, liver injury, poor diet	Condition of 3.23% of patients worsened	[74]
		Trial no: ChiCTR2000030254; 1600 mg favipiravir twice daily on Day 1; 600 mg favipiravir twice daily until end of study	Wuhan, China	116	61.21	$-$	$-$	No severe adverse effects; mild adverse effects included raised serum uric acid, digestive tract reactions, irregular liver function tests, and psychiatric symptoms	$-$
Lopinavir/ritonavir	Both inhibit SARS-CoV main protease; ritonavir also inhibits CYP450-3A4, responsible for metabolism of lopinavir	Trial no: ChiCTR2000029308; 14 days: lopinavir: 400 mg twice daily; ritonavir: 100 mg, twice daily	Wuhan, China	99	45.5	–	19.2	Gastrointestinal adverse events : nausea, vomiting, diarrhea	Lopinavir–ritonavir treatment stopped early in 13.8% of cases because of adverse events; results with lopinavir–ritonavir similar to standard care	[68]
		lopinavir (200 mg)/ritonavir (50 mg) twice daily	Taiwan	5	100	0	0	Vomiting, diarrhea	Results with lopinavir–ritonavir similar to standard care	[67]
Umifenovir	Prevents interaction of S protein with ACE2 host cell receptor	9 days: 400 mg/three times daily	Wuhan, China	36	33	67	0	–	–	[82]
		200 mg/three times daily	Wuhan, China	49	59.2	–	–	Usual adverse effects (nausea, diarrhea) minimal in this study; bradycardia observed in 1 patient	–	[77]
		Trial no: ChiCTR2000030254; 200 mg/three times daily for 10 days	Wuhan, China	120	51.67	–	–	Increased serum uric acid, digestive tract reactions, psychiatric reactions	–	[72]
Tocilizumab	Binds to IL-6R, inhibiting CRS	13 days: 400 mg once i.v.	Wuhan, China	21	100	–	0	No adverse drug reactions	–	[101]