Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2022 Jul;179(13):3250-3267.
doi: 10.1111/bph.15843. Epub 2022 Apr 11.

Niclosamide-A promising treatment for COVID-19

Shivani Singh  1 , Anne Weiss  2   3 , James Goodman  4 , Marie Fisk  4 , Spoorthy Kulkarni  4 , Ing Lu  4 , Joanna Gray  4 , Rona Smith  4   5 , Morten Sommer  2   6 , Joseph Cheriyan  4   5
Affiliations
Review

Niclosamide-A promising treatment for COVID-19

Shivani Singh et al. Br J Pharmacol. 2022 Jul.

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.

Keywords: COVID-19; clinical trials; niclosamide; repurposing.

PubMed Disclaimer

Conflict of interest statement

JC and RS acknowledge institutional grants from Union Therapeutics for the conduct of investigator initiated clinical trials of niclosamide. MS is a shareholder of UNION Therapeutics, and AW benefits from an employee incentive scheme. The other authors declare no conflict of interest.

Figures

FIGURE 1
FIGURE 1
The chemical structure of niclosamide, C13H8Cl2N2O4
FIGURE 2
FIGURE 2
Potential mechanisms of antiviral activity have been illustrated in this figure. These include (i) endosomal pH neutralization to prevent viral replication, (ii) promotion of autophagy via inhibition of S‐phase kinase‐associated protein 2 (SKP2), (iii) decreased mucus plugging via inhibition of TMEM16A (calcium activated chloride channel; CaCC) and (iv) prevention of syncytia formation by ion channel inhibition. Abbreviation: BCN1, beclin‐1; ATG14, autophagy related 14; SARS‐COV‐2, severe acute respiratory syndrome coronavirus‐2. Created with BioRender.com
FIGURE 3
FIGURE 3
COVID‐19 clinical trials investigating niclosamide. Study references refer to National ClinicalTrials.gov (NCT), Clinical Trials Registry – India (CTRI) or EU Clinical Trials Register (EUCTR), where applicable, are included in Table 2. The majority of studies are dual listed on the WHO International Clinical Trials Registry Platform (ICTRP). Study NCT04372082 was terminated prior to randomization and is therefore excluded from the figure
See this image and copyright information in PMC

References

    1. Abdulamir, A. S. , Gorial, F. I. , Saadi, S. J. , Maulood, M. F. , Hashim, H. A. , Alnuaimi, A. S. , & Abdulrrazaq, M. K. (2021). A randomised controlled trial of effectiveness and safety of Niclosamide as add on therapy to the standard of care measures in COVID‐19 management. Annals of Medicine and Surgery, 69, 102779. 10.1016/j.amsu.2021.102779 - DOI - PMC - PubMed
    1. Alexander, S. P. , Christopoulos, A. , Davenport, A. P. , Kelly, E. , Mathie, A. , Peters, J. A. , Veale, E. L. , Armstrong, J. F. , Faccenda, E. , Harding, S. D. , Pawson, A. J. , Southan, C. , Davies, J. A. , Abbracchio, M. P. , Alexander, W. , Al‐hosaini, K. , Bäck, M. , Barnes, N. M. , Bathgate, R. , … Ye, R. D. (2021). THE CONCISE GUIDE TO PHARMACOLOGY 2021/22: G protein‐coupled receptors. British Journal of Pharmacology, 178(S1), S27–S156. 10.1111/bph.15538 - DOI - PubMed
    1. Alexander, S. P. , Fabbro, D. , Kelly, E. , Mathie, A. , Peters, J. A. , Veale, E. L. , Armstrong, J. F. , Faccenda, E. , Harding, S. D. , Pawson, A. J. , Southan, C. , Davies, J. A. , Beuve, A. , Brouckaert, P. , Bryant, C. , Burnett, J. C. , Farndale, R. W. , Friebe, A. , Garthwaite, J. , … Waldman, S. A. (2021a). THE CONCISE GUIDE TO PHARMACOLOGY 2021/22: Catalytic receptors. British Journal of Pharmacology, 178(S1), S264–S312. 10.1111/bph.15541 - DOI - PubMed
    1. Alexander, S. P. , Fabbro, D. , Kelly, E. , Mathie, A. , Peters, J. A. , Veale, E. L. , Armstrong, J. F. , Faccenda, E. , Harding, S. D. , Pawson, A. J. , Southan, C. , Davies, J. A. , Boison, D. , Burns, K. E. , Dessauer, C. , Gertsch, J. , Helsby, N. A. , Izzo, A. A. , Koesling, D. , … Wong, S. S. (2021b). THE CONCISE GUIDE TO PHARMACOLOGY 2021/22: Enzymes. British Journal of Pharmacology, 178(S1), S313–S411. 10.1111/bph.15542 - DOI - PubMed
    1. Al‐Gareeb, A. , Gorial, F. , & Mahmood, A. (2019). The anti‐rheumatoid activity of niclosamide in collagen‐induced arthritis in rats. Archives of Rheumatology, 34(4), 426–433. 10.5606/ArchRheumatol.2019.7100 - DOI - PMC - PubMed

Publication types