Neuraminidase uses

These drugs are inhibitors of neuraminidases produced by influenza A and B and are currently active against both H3N2 and H1N1 strains. These viral enzymes cleave sialic acid residues from viral proteins and surface proteins of infected cells. They function to promote virion release and to prevent clumping of newly released virions. By interfering with these actions, neuraminidase inhibitors impede viral spread. Decreased susceptibility to the drugs is associated with mutations in viral neuraminidase, but worldwide resistance remains rare. Unlike the adamantane analogs, oseltamivir and zanamivir are effective against both Type A and Type B influenza viruses. They do not interfere with the immune response to influenza A vaccine. Administered prior to exposure, neuraminidase inhibitors prevent infection, and, when administered within the first 24 to 48 hours after the onset of infection, they have a modest effect on the intensity and duration of symptoms.Influenza viruses employ a specific neuraminidase that is inserted into the host cell membrane for the purpose of releasing newly formed virions. Oseltamivir and zanamivir are transition-state analogs of the sialic acid substrate and serve as inhibitors of the enzyme activity. Oseltamivir is an orally active prodrug that is rapidly hydrolyzed by the liver to its active form. Zanamivir, on the other hand, is not active orally and is either inhaled or administered intranasally. Both drugs are eliminated unchanged in the urine