Tamiflu (Molecule of the Month for December 2005)
Tamiflu (Oseltamivir) is an antiviral drug for the treatmant of influenza A and B. It works by blocking the function of viral neuraminidase protein. Tamiflu was the first orally active neuraminidase inhibitor commercially developed. It was developed by Gilead Sciences and is currently marketed by Roche. The increasing fears about the potential of bird flu turning into a new influenza pandemic, has focused attention on oseltamivir, especially since production capacity is limited and governments are stockpiling the drug.
The synthesis of Oseltamivir is a major feat of organic chemistry, it requires over 30 synthetic steps to make it from the naturally available (?)-shikimic acid. Apart from the complex synthetic route the availability of shikimic acid causes problems, it is exracted from spice Chinese star anise, so due to the demand for Tamiflu, Roche has had to buy up 90% of the worlds supply of spice.
The shortage of Tamiflu has prompted some individuals to stockpile Tamiflu. Sadly therefore there has been a market online selling of Tamiflu which is more than likely to be based on illegally imported and/or dangerous counterfeit pharmaceuticals. The US Food and Drug Administration (FDA) in early Dec 2005 took action against a number of websites requiring them to stop fraudulently marketing Tamiflu as a cure for bird flu.
Update by Karl Harrison
(Molecule of the Month for December 2005 )