Research has revealed that nafamostat mesylate, when injected in the nasal cavity of Syrian hamsters could decrease the initial SARS-CoV-2 viral load. This effect was however temporary. The spike protein of the virus infects the human cells by binding to ACE2. In-situ RNA mapping has revealed that the ACE2 expression is the highest in the nose. Nafamostat mesylate an anticoagulant has been approved for use in Japan. It has also shown the potential to inhibit spike protein-mediated membrane fusion thus inhibiting the entry of SARS-CoV-2 in the lungs.
In this study, nafamostat mesylate was applied intranasally to female Syrian Hamsters and after 5 minutes, SARS-CoV-2 was inoculated in the nose. Viral loads were analyzed 1 and 3 days after the infection. The viral loads in the animals treated with nafamostat mesylate in lipid had significantly reduced viral loads. However, there was no difference in the viral loads after 3 days. This concludes that the effect is temporary but nafamostat mesylate is effective in reducing the viral loads. The researchers suggest that a single application may not be enough to achieve sufficient protection. They suggest that nafamostat mesylate could be applied as an inhalator or spray multiple times.
Ref link: https://www.biorxiv.org/content/10.1101/2020.11.09.372375v1