Environmental perspectives of COVID-19 outbreaks: A review

Table 4 Recommended drugs for coronavirus disease 2019 treatments (Food and Drug Administration and World Health Organization)

Common drugs	Dose	Mechanism
Chloroquine; Antimalarial	50% for GFR < 10 mL/min	In vitro activity and has immunomodulating properties
		Inhibits viral enzymes or processes such as viral DNA and RNA polymerase, viral protein glycosylation, virus assembly, new virus particle transport, and virus release
		ACE2 inhibition due to acidification at cell membrane surface, inhibits fusion of virus, and cytokine release
Hydroxychloroquine; Antimalarial	800 mg orally on day one, followed by 400 mg/d orally for four to seven days	Same as chloroquine
Chloroquine phosphate; Antimalarial	1 g orally on day one, followed by 500 mg/d orally for four to seven days	Same as chloroquine
Remdesivir; Nucleoside Analogue	200 mg IV on day 1 followed by 100 mg IV daily on days two to five or 200 mg IV on day 1 followed by 100 mg IV daily on days two to ten	In vitro activity; Inhibitor of RNA-dependent RNA polymerases (RdRps)
		Remdesivir-TP competes with adenosine-triphosphate for incorporation into nascent viral RNA chains
		Once incorporated into the viral RNA at position i, RDV-TP terminates RNA synthesis at position i+3
		Because RDV-TP does not cause immediate chain termination (i.e., 3 additional nucleotides are incorporated after RDV-TP), the drug appears to evade proofreading by viral exoribonuclease (an enzyme thought to excise nucleotide analogue inhibitors)
Azithromycin; Macrolide Antibacterial	500 mg on day one, followed by 250 mg daily for four days	Prevents bacterial superinfection, has immunomodulatory action on pulmonary inflammatory disorders
		Downregulates inflammatory responses and reduces excessive cytokine production associated with respiratory viral infections; however, its direct effects on viral clearance are uncertain
		Immunomodulatory mechanisms include reducing chemotaxis of neutrophils (PMNs) to lungs by inhibiting cytokines (i.e., IL-8), inhibition of mucus hypersecretion, decreased production of ROS, accelerating neutrophil apoptosis, blocking activation of nuclear transcription factors
Lopinavir; Ritonavir; HIV protease inhibitor	400 mg/ritonavir 100 mg orally twice daily for up to 21 d	In vitro animal model studies show potential activity for other coronaviruses (SARS-CoV and MERS-CoV)
		Lopinavir and ritonavir may bind to Mpro, a key enzyme for virus replication and suppress virus activity
Tocilizumab; Interleukin-6 (IL-6) Receptor-InhibitingMonoclonal Antibody	4-8 mg/kg infused over more than 60 min (additional dose after 12 h)	Cytokine release syndrome; Inhibits IL-6-mediated signaling by competitively binding to both soluble and membrane-bound IL-6 receptors. IL-6 involved in T-cell activation, immunoglobulin secretion induction, hepatic acute-phase protein synthesis initiation, and hematopoietic precursor cell proliferation and differentiation stimulation
Baloxavir; Antiviral	80 mg orally on day 1 and on day 4, and another dose of 80 mg on day 7 (as needed); not to exceed 3 total doses	Active against influenza viruses; In vitro antiviral activity against SARS-CoV-2 demonstrated in one trial
Favipiravir; Antiviral	1600 mg twice daily on day 1, then 600 mg twice daily for 7-10 d; Severe: 1600 mg every 12 h on day 1, then 600 mg every 12 h days 2-10	In vitro activity against Vero E6 cells

SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2.