**17. Umifenovir (also known as arbidol)**

Umifenovir (also known as arbidol) is a potent antiviral drug with a novel mechanism that inhibits viral envelope fusion by targeting the S protein/ACE2 interaction [109]. Based on *in vitro* studies demonstrating action against SARS, the medication is now authorized in Russia and China for the treatment and prevention of influenza. It is also gaining interest in treating COVID-19 [110]. The current influenza treatment dosage of 200 mg orally every 8 hours is being investigated for COVID-19 therapy (NCT04260594). In China, only limited clinical experience with umifenovir for COVID-19 has been reported. In a non-randomized analysis of 67 COVID-19 patients, therapy with umifenovir for 9 days was related with reduced fatality rates and higher discharge rates than patients who did not get the drug [111]. This finding cannot approve the success of umifenovir for COVID-19 treatment, but several RCTs are required for further investigation of this agent.
