Camostat mesylate against SARS-CoV-2 and COVID-19-Rationale, dosing and safety

Basic Clin Pharmacol Toxicol. 2021 Feb;128(2):204-212. doi: 10.1111/bcpt.13533. Epub 2020 Nov 22.


The coronavirus responsible for COVID-19, SARS-CoV-2, utilizes a viral membrane spike protein for host cell entry. For the virus to engage in host membrane fusion, SARS-CoV-2 utilizes the human transmembrane surface protease, TMPRSS2, to cleave and activate the spike protein. Camostat mesylate, an orally available well-known serine protease inhibitor, is a potent inhibitor of TMPRSS2 and has been hypothesized as a potential antiviral drug against COVID-19. In vitro human cell and animal studies have shown that camostat mesylate inhibits virus-cell membrane fusion and hence viral replication. In mice, camostat mesylate treatment during acute infection with influenza, also dependent on TMPRSS2, leads to a reduced viral load. The decreased viral load may be associated with an improved patient outcome. Because camostat mesylate is administered as an oral drug, it may be used in outpatients as well as inpatients at all disease stages of SARS-CoV-2 infection if it is shown to be an effective antiviral agent. Clinical trials are currently ongoing to test whether this well-known drug could be repurposed and utilized to combat the current pandemic. In the following, we will review current knowledge on camostat mesylate mode of action, potential benefits as an antiviral agent and ongoing clinical trials.

Keywords: Antiviral drugs < Viral infections; Camostat mesylate; Infection < Immunotoxicology; Lung; drug repurposing; pulmonary or respiratory system < Respiratory toxicology; tmprss2.

Publication types

  • Review

MeSH terms

  • Animals
  • Antiviral Agents / administration & dosage
  • Antiviral Agents / adverse effects
  • Antiviral Agents / therapeutic use*
  • COVID-19 Drug Treatment*
  • Drug Repositioning
  • Esters / administration & dosage
  • Esters / adverse effects
  • Esters / therapeutic use*
  • Guanidines / administration & dosage
  • Guanidines / adverse effects
  • Guanidines / therapeutic use*
  • Humans
  • Mice
  • Patient Safety
  • Serine Endopeptidases / drug effects
  • Serine Proteinase Inhibitors / administration & dosage
  • Serine Proteinase Inhibitors / adverse effects
  • Serine Proteinase Inhibitors / therapeutic use*


  • Antiviral Agents
  • Esters
  • Guanidines
  • Serine Proteinase Inhibitors
  • camostat
  • Serine Endopeptidases
  • TMPRSS2 protein, human

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