Background: The recent serious outbreak of Covid19 has required urgent medical treatments for numerous patients. No clinically active vaccines or antiviral agents are available for Covid19. According to several studies, Chloroquine
(CQ) and Hydroxychloroquine (HCQ) have shown promises as Covid19 antiviral especially when administered with
Objective: Here we review the rationale behind this use. CQ/HCQ is effective against Covid19 in-vitro and in-vivo laboratory studies. Therapy in Covid19 infected patients with CQ/HCQ is supported by evidence of trials and field experiences from
Methods: The relevant works are reviewed. The presence or absence of conflict of interest is weighed against the conclusions.
Results: CQ/HCQ has been used with success in mild cases or medium severity cases. No randomized controlled trial has
however been conducted to support the safety and efficacy of CQ/HCQ and AZM for Covid19. Prophylaxis with CQ/HCQ
is more controversial, but generally not having side effects, and supported by pre-clinical studies. The mechanism of action
against Covid19 is unclear. More research is needed to understand the mechanisms of actions CQ/HCQ have against
Covid19 infection, and this requires investigations with nanoscale imaging of viral infection of host cells.
Conclusion: Most of the published works indicate CQ/HCQ is likely effective against Covid19 infection, almost 100% in
prophylaxis and mild to medium severity cases, and 60% in late infection cases. The percentage of positive works is larger if
works conducted under a probable conflict of interest are excluded from the list.