1-Methyl-4-[[(phenylmethyl)amino]carbonyl]pyridiniumiodide (CAS# 201349-37-3) is Enisamium iodide (Amizon?, Farmak) is approved for clinical use in the treatment of influenza in 11 countries which includes Ukraine, Russia, Belarus, Kazakhstan, and Uzbekistan. Enisamium iodide exhibited antiviral activity against influenza viruses in vitro, supporting the reported clinical efficacy against influenza virus infections.