TABLE 2.

Clinical trials supporting HCQ use. The following databases were searched: Cochrane, embase, Medline, New England Journal of Medicine and PubMed. A total of five trials supported the use of HCQ in patients with COVID-19. All of them except one were observational cohort studies.

Evidence supporting the use of HCQ
Study	Study type	Country	Population size	Results	Ref
Efficacy of hydroxychloroquine in patients with COVID-19: Results of a randomized clinical trial	Single-center RCT	China	62	A quicker recovery was noted in the HCQ-treated group compared to the control group. Studied outcomes included:• Time to clinical recovery • clinical progression • radiological progression	(Chen Z. et al., 2020)
Hydroxychloroquine and azithromycin as a treatment of COVID-19: Results of an open-label non-randomized clinical trial	Single-center, single-arm, non-randomized clinical trial	France	36	A quicker reduction in viral load was noted in the HCQ-treated group. A synergistic effect was prompted by the addition of azithromycin to the HCQ regimen. Studied outcomes included: • Virologic clearance achieved after 6 days of treatment • time to negative conversion • clinical progression • experienced side effects	(Gautret et al., 2020a)
Clinical and microbiological effect of a combination of hydroxychloroquine and azithromycin in 80 COVID-19 patients with at least a 6-day follow up: A pilot observational study	Single-center, uncontrolled, non-comparative observational study	France	80	Quicker reduction in viral load, shorter hospital stay, and improved outcomes were noted among the patients after an average of 5 days of treatment. Studied outcomes included: • Virologic clearance achieved up till day 12 of treatment • clinical outcomes • length of hospital stay	(Gautret et al., 2020b)
Early treatment of COVID-19 patients with hydroxychloroquine and azithromycin: A retrospective analysis of 1,061 cases in marseille, France	Single-center non-comparative, retrospective study	France	1,061	The use of HCQ combined with azithromycin was linked to improved mortality, clinical outcomes, and virologic clearance. Studied outcomes included: • Mortality clinical worsening (need for intensive care, and prolonged hospital stay) • virologic clearance	(Million et al., 2020)
Low dose of hydroxychloroquine reduces fatality of critically ill patients with COVID-19	Single-center comparative, retrospective study	China	550	The use of HCQ in critically ill COVID-19 patients was associated with improved survival, and reduced mortality rate. Studied outcomes included: • Length of hospital stay • mortality rate	(Yu, 2020)