Niclosamide—A promising treatment for COVID‐19

Abstract

Vaccines have reduced the transmission and severity of COVID‐19, but there remains a paucity of efficacious treatment for drug‐resistant strains and more susceptible individuals, particularly those who mount a suboptimal vaccine response, either due to underlying health conditions or concomitant therapies. Repurposing existing drugs is a timely, safe and scientifically robust method for treating pandemics, such as COVID‐19. Here, we review the pharmacology and scientific rationale for repurposing niclosamide, an anti‐helminth already in human use as a treatment for COVID‐19. In addition, its potent antiviral activity, niclosamide has shown pleiotropic anti‐inflammatory, antibacterial, bronchodilatory and anticancer effects in numerous preclinical and early clinical studies. The advantages and rationale for nebulized and intranasal formulations of niclosamide, which target the site of the primary infection in COVID‐19, are reviewed. Finally, we give an overview of ongoing clinical trials investigating niclosamide as a promising candidate against SARS‐CoV‐2.

Magic bullets, magic shields, and antimicrobials in between

“…Unsurprisingly, as with IAs, dexamethasone is also used to treat cancers, including leukaemia and lymphoma [ 257 ]. It is important, therefore, to highlight both the pan-pathogen potential (and therefore pandemic-preparedness potential) and MPT potential of IAs and pure magic shield immunomodulators [ 258 , 259 ].…”

Presumed veterinary niclosamide-induced retinal toxicity in a human: a case report

“…Other proposed mechanisms of action include suppression of STAT3 and NF-ĸB pathways [ 11 ]. Moreover, recent publications have shown the potential usage of this drug in the management of COVID-19 [ 12 ]. In addition, an animal study by a Liu et al .…”

Targeting SARS-CoV-2 and host cell receptor interactions

“…Besides interfering with virus-receptor interactions, repurposed drugs that block spike-mediated cell fusion ( Mediouni et al, 2022 ; Chen et al, 2020 ; Riva et al, 2020 ) or enzymatic activities of ACE2 (MLN-4760), TMPRSS2 (Camostat mesylate and Nafamostat), cathepsins (Eicoplanin, calpain inhibitor II, XII), furin (reviewed in Nepali et al, 2022 ) have been described. Indeed, a few repurposed drugs have entered the clinic for treatment of COVID-19 and they include Niclosamide (oral or inhaled formulation; phase III) which acts as a protonophore to interfere with viral entry and egress ( Singh et al, 2022 ), Nafamostat ( Zhuravel, 2021 ; phase II/III), Camostat (phase I/II), Amiodarone and Verapamil (inhibit endosomal processing ( Stadler et al, 2008 ; phase II/III), Umifenovir (Arbidol; targets S-protein and prevents viral fusion; Nojomi et al, 2020 ; phase III/IV).…”