Abstract
Influenza or simple ‘flu’ is a very common virus mediated infection in upper respiratory tract caused by Flu viruses,
belonging to the Orthomyxoviridae family, are generally classified as A, B, and C, on the basis of the antigenic differences
of their nuclear and matrix proteins. This causes pandemic in eastern world in majority with few other cases of western globe
at current. “The Spanish Influenza Pandemic of 1918” which claimed about 50 million people worldwide was the best
scientific documented evidence, followed by “Hongkong Disaster” of 1968 which killed about 70000 people in Asia and
34000 people in United States of America. With the drug design researches Sialic acid based, Cyclohexane based & benzoic
acid based designed drugs were marketed successfully. Six drugs are currently available for the treatment or prophylaxis of
influenza infections: the adamantanes (AM) (amantadine and rimantadine) and the newer class of neuraminidase inhibitors
(NAI) (zanamivir, Laninamivir, Peramivir and oseltamivir). But with the passage of time efficacy of drugs are reducing due
to genotypic, phenotypic and clinical resistance. It can be used therapeutically for prophylactic use in children, who suffers
largely in winters & breast feeding mothers. NAIs are category C drugs which makes them not cent percent fit for safe
administration and lack of clinical data with large variability in obtained results restricts its frequent use. For complete
eradication better drug design, drug discovery, synthetic & drug development research approaches are needed to develop
cost effective formulations along with necessary improvement in primary health measures.

Key words: Neuraminidase Inhibitors, Influenza, Oseltamivir, Drug design, Drug synthesis, Tamiflu resistance