Zanamivir (GG167) is a guanido-neuraminic acid that is used to inhibit NEURAMINIDASE.

Influenza A:0.95 nM, Influenza B:2.7 nM

Zanamivir reduces pulmonary viral titers and decreases morbidity and mortality rates in a lethal murine model infected with the virus.

Zanamivir effectively reduces viral replication in vitro by inhibiting the influenza neuraminidase and preventing the cleavage of sialic acid residues. This interference blocks the spread of progeny viruses in mucosal secretions and lowers viral infectivity. Furthermore, Zanamivir diminishes the area of plaques formed by neuraminidase-deficient mutants, indicating that its action in disrupting cell-cell fusion is independent of its neuraminidase inhibition activity. The compound also prevents the adhesion and fusion of persistently infected cells with uninfected erythrocytes. Assessment through lipid mixing and content mixing reveals that Zanamivir does not affect erythrocyte adhesion but does inhibit HA2b-red blood cell fusion. Additionally, Zanamivir leads to decreased sensitivity in influenza A/H1N1 variants His274Asn, His274 gly, His274Ser, and His274 gln.