[Neuraminidase inhibitors in therapy of influenza]

Neuraminidase promotes influenza virus release from infected cells and facilitates virus spread within the respiratory tract. Several specific inhibitors of these enzyme have been developed. Zanamivir and oseltamivir are the nowadays available neuraminidase inhibitors. In contrast to amantadine and rimantadine, which target the M2 protein of influenza A, they inhibit the replication of both influenza A and B. Zanamivir is delivered by inhalation because of its low oral bioavailability. Oseltamivir can be administered orally. Early treatment reduces the severity and duration of illness and associated complications. These drugs are not effective at afebrile, mild courses, or if the influenza symptoms have existed already for more than 2 days. They are not effective against other respiratory viruses. For an optimal usage of the neuraminidase inhibitors a rapid and reliable diagnosis is necessary. The clinical diagnosis is sufficient only in proven epidemics. An increased availability of sensitive and specifically diagnostical tests is necessary for individual therapy decisions. The influenza vaccination is the most effective measure against influenza.