Neuraminidase inhibitors in the therapy of influenza

Neuraminidase promotes influenza virus release from infected cells and faci litates virus spread within the respiratory tract. Several specific inhibit ors of these enzyme have been developed. Zanamivir and oseltamivir are the nowadays available neuraminidase inhibitors. In contrast to amantadine and rimantadin, which target the M2 protein of influenza A, they inhibit the re plication of both influenza A and B. Zanamivir is delivered by inhalation b ecause of its low oral bioavailability. Oseltamivir can be administered ora lly. Early treatment reduces the severity and duration of illness and assoc iated complications. These drugs are not effective at afebrile, mild course s, or if the influenza symptoms have existed already for more than 2 days. They are not effective against other respiratory viruses. For an optimal us age of the neuraminidase inhibitors a rapid and reliable diagnosis is neces sary. The clinical diagnosis is sufficient only in proven epidemics. An inc reased availability of sensitive and specifical diagnostical tests is neces sary for individual therapy decisions. The influenza vaccination is the most effective measure against influenza.