- Neuraminidase inhibitor drugs
There are currently two neuraminidase inhibitor drugs licensed for treatment and chemoprophylaxis of influenza; zanamivir [Relenza®] and oseltamivir [Tamiflu®]. Both drugs act by inhibiting the enzyme function of the viral neuraminidase protein, thus preventing the virus from budding from the host cell.
The neuraminidase inhibitor drugs are effective against both influenza A and B viruses, unlike the other class of antiviral drugs, the M2 inhibitor adamantanes (amantadine [Symmetrel®] and rimantadine [Flumadine®]), which are only effective against influenza A.
The adamantanes are associated with 
rapid development of resistance and important side effects, including delirium and seizures that occur mostly in elderly persons taking higher doses.
Evaluation and registration of antiviral agents is undertaken at a national level by local authorities. There are no international regulations and countries publish their own guidance.
Obtaining drugs for Neuraminidase Inhibition testing
It is possible to obtain the pure substance of each of the neuraminidase inhibitor drugs for laboratory testing of neuraminidase inhibition by contacting the manufacturers, Roche and GlaxoSmithKline, directly.
To obtain oseltamivir phosphate phosphate (pro-drug) and/or active metabolite (oseltamivir carboxylate) from Roche, please complete the 
attached formand return to the email address specified on the form.
To obtain the pure substance of Zanamivir for laboratory testing purposes, please contact Lorriane.X.Bray@gsk.com if in the UK, or Carol.A.Jenkins@gsk.com if in the USA.
Links to NI Drug Technical Information
Technical information on oseltamivir [Tamiflu®] is available from Roche by navigating to the ‘antiviral’ information in the section for healthcare professionals
Technical information on zanamivir [Relenza®] is available here
For general information on oseltamivir, click here
For general information on zanamivir, click here
