What medications have been used to treat bird flu?
Tamiflu: Tamiflu is the drug most frequently recommended for H5N1 or avian flu. This antiviral drug was originally developed in 1999 to reduce the severity of traditional flu. Countries all over the world have been stockpiling Tamiflu. The US government has urged states to stockpile Tamiflu. Some states in the U.S. have considered stockpiling enough Tamiflu to treat 25% of their population. Despite increases in production, Tamiflu remains in short supply and is not effective for everyone.
The most difficult problem with Tamiflu is that it must be taken within 48 hours of the onset of the first symptoms for optimal effectiveness. This presents a number of problems:
กค The initial symptoms..fever, cough, mucus..are common to many conditions.
กค In many countries it is not readily feasible to get a prescription within 48 hours.
กค Tamiflu is in short supply and is expensive.
กค Many doctors do not recognize bird flu symptoms or know the dosages generally needed to be effective in the treatment of the H5N1 virus.
The normal dose to date for other forms of influenza has been 75 mg. twice per day for five days, but for the H5N1 virus the most effective dosage for humans has been 150 mg. twice per day for 10 days, 4 times the regular dosage. In May, 2006, the World Health Organization recommended that Tamiflu be given with other anti-viral medications such as Relenza and Peramivir when feasible.
Relenza: With Tamiflu in such short supply, attention is now turning toward Relenza. Whereas Tamiflu is taken orally, Relenza requires an inhaler. Within months of Relenza's approval however, there were reports of respiratory problems and fatalities in users who had asthma or other pulmonary diseases. However, with the high death rate of bird flu, (56% of the cases reported from 2003 to 2006), medical professionals are revisiting the proper use of Relenza. Additionally, in mid-October of 2005, it was announced that a sample of the avian flu virus taken from a 14 year old Vietnam girl in February of 2005 was a form that was resistant to Tamiflu in a laboratory test. Many countries are now stockpiling Relenza as well as Tamiflu, for fear that the current strains will become resistant to Tamiflu.
Tamiflu and Relenza have both been used successfully in Asia, saving people's lives. However, like all medications, they do not work for everyone.
Peramivir: Another drug in the pipeline could be Peramivir Peramivir failed in clinical trials in 2001 in part because not enough of it got into the blood stream when taken orally. With the current shortage of medications in the US to treat bird flu in the event of a pandemic, BioCryst Pharmaceuticals, the manufacturer, is now resurrecting Peramivir in its laboratories and testing it in a form that is given intravenously or injected. Although the drug is nowhere near formal approval by the FDA at this time, the company says that it could be quickly manufactured on an emergency basis.