About Oseltamivir Antiviral,Neuraminidase inhibitor Mechanism of Action of Oseltamivir Oseltamivir is an ethyl ester prodrug requiring ester hydrolysis for conversion to active form oseltamivir carboxylate. Oseltamivir is a neuraminidase inhibitor, serving as a competitive inhibitor towards sialic acid, found on the surface proteins of normal host cells. By blocking the activity of the viral neuraminidase (NA) enzyme, oseltamivir prevents new viral particles from being released by infected cells. Indications for Oseltamivir Treatment and prevention of infections due to influenza A and B viruses. Interactions for Oseltamivir Oseltamivir+Probenecid: Oseltamivir has its toxicity increased by probenecid.