Table 1.

The main drug classes used as potential treatments in COVID-19.

Drug	Class	Rationale use	Clinical experience	Observations
(Hydroxy)chloroquine	Antimalarial	Changes the pH of the cell membrane surface and thus inhibits the fusion of the virus with the cell membrane. Inhibits nucleic acid replication, glycosylation of viral proteins, assembly of the virus, and release of the virus from the infected cell.	In vitro activity against SARS-CoV-2, as well as some positive results in the treatment of patients with COVID-19 (32). A recent study showed faster virus clearance in patients with COVID-19 who received hydroxychloroquine (33). Initial dose: 600 mg (of chloroquine) followed by 300 mg (of chloroquine) 12 h later on day 1, then 300 mg (of chloroquine) twice daily on days 2–5.	It has been widely used in long-term treatments in rheumatology, without generating significant side effects.
Camostat	Inhibits TMPRSS2 protease	Inhibition of cell entry Prevents SARS-CoV-2 coronavirus infection	An in vitro study in a mouse model demonstrated the efficacy of camostat in protecting mice from death from a lethal SARS-CoV infection with a 60% survival rate (34). It is considered that doses of 600 mg (200 mg, three times) of camostat daily are expected to reduce SARS-CoV-2 infection; but human clinical trials are needed (35).	Mesylate camostat, approved in the treatment of inflammation of the pancreas in Japan.
Remdesivir	Antiviral for Ebola	Inhibits RNA-dependent RNA polymerase, prematurely blocking RNA transcription.	Broad antiviral spectrum; Efficacy against coronaviruses, both in vitro and in vivo studies; The safety profile has been demonstrated in Ebola studies; Superior efficacy of the Lopinavir/Ritonavir/IFNbeta combination in animal model studies. Adults and children weighing 40 kg or more: Loading dose of 200 mg by IV infusion on day 1, followed by 100 mg by IV infusion once daily on days 2–10 or followed by 100 mg by IV infusion once daily on days 2–5.	FDA (US) has authorized the use of remdesivir in severe infection with the new coronavirus SARS-CoV-2, through the Special Emergency Use Authorization (EUA).
Lopinavir /Ritonavir (LPV/RTV) combination	Antiviral for HIV	Lopinavir is a protease inhibitor used to treat HIV infection in combination with ritonavir to increase its availability.	Lopinavir has some degree of activity against coronaviruses in vitro, including SARS-CoV-2. The clinical data published so far have been inconsistent. Three observational studies failed to identify a reduction in the duration of virus excretion in patients treated with lopinavir/ritonavir compared to favipiravir or placebo, while during the Wuhan epidemic the use of lopinavir/ritonavir resulted in faster elimination of the virus. In the case of early administration, in the initial viral phase, in the first 10 days after the onset of symptoms (36). LPV/RTV (COVID-19): LPV 400 mg/RTV 100 mg orally twice daily for 10–14 days (37).	This drug remains as another alternative, in the absence of more effective drugs. An additional plus is related to the form of liquid administration—usable in orotracheal intubated patients and in newborns.
Umifenovir	Antiviral for influenza viruses	Blocking the penetration of the virus into cells (fusion inhibitor) and the immunomodulatory effect.	In patients with uncomplicated pneumonia in COVID-19, the combination of umifenovir (200 mg every 8 h) with lopinavir/ritonavir resulted in faster clearance of the virus at the nasopharyngeal level and a faster regression of lung imaging changes compared to patients receiving monotherapy with lopinavir/ritonavir (38). 200 mg orally 3 times daily for duration of 7–10 days or longer (39).	Reduced side effects
Favipiravir	Antiviral for flu and Ebola	RNA polymerase inhibitor	Used in China in patients of childbearing potential only if they had a negative pregnancy test and always associated with contraceptive medication during treatment and at least 7 days after stopping treatment; Doses: 1,600 mg every 12 h on the first day, then 600 mg every 12 h for 7–14 days. The drug cannot be administered to children and pregnant women (teratogenic risk)	Teratogenic effects
Tocilizumab	Immunomodulatory	IL-6 receptor antagonist	Has been used in a subset of patients with severe COVID-19 in whom there is excessive activation of inflammation (“cytokine storm”). The effectiveness of tocilizumab has been shown in small groups of patients; after administration of 1–2 doses, afebrility was obtained in all patients, as well as a decrease in oxygen requirements and partial correction of lymphopenia. The results obtained with tocilizumab combined with corticosteroids were favorable, following the administration of doses of 8 mg/kgc, repeated at 8–12 h, up to a maximum of 3 administrations (40).	Risks associated with the reactivation of tuberculosis, hepatic cytolysis, hypercholesterolemia.