Updated: 03/18/2009 05:00 AMBy: Kafi Drexel Just a few years...

Updated: 03/18/2009 05:00 AM
By: Kafi Drexel

Just a few years ago, Tamiflu was one of only two antiviral drugs recommended to fight some of the most serious cases of flu. But new research from the Centers for Disease Control shows the medication no longer works for more than 98 percent of one of the most common strains, influenza A or H1N1.



"The fact that it is all-resistant to Tamiflu means we have lost a major weapon in treating people who are sick with this virus. We've also lost a really important weapon in preventing people who are exposed to ill people from becoming ill," said Dr. Anne Moscona, New York Presbyterian, Weill Cornell Medical Center.



Antiviral drugs are only necessary for patients severely sick with flu, or who are considered high-risk. Doctors say, the good news is we've had a relatively mild flu season so far.



But the virus changes from year to year. And they say the fact that one of the most common drugs has pretty much lost its effectiveness against one of the most common strains should be a red flag for seasons to come.


Popular flu medicine losing effectiveness
One of the most widely used flu medications is no longer effective against one of the most dominant strains of the virus. As Kafi Drexel reports, this is not great news in the midst of flu season.


"Although there is an increased resistance to this medication, Tamiflu doesn't seem to be related to the use of Tamiflu. So next year we may be dealing with a totally different situation and the viruses may be again susceptible," said Dr. Neil Schachter, Mt. Sinai Medical Center.



"While this season of flu is relatively mild and also resistant to Tamiflu a more virulent, serious type of flu could also be resistant in the future and we need to start thinking about ways of dealing with that possibility," said Moscona.



There are alternatives to Tamiflu. Anticipating an increase in resistance to the drug, the CDC already put out advisories to doctors for this season advising them to treat with Relenza and or to use a combination of Tamiflu with an older drug, Ramantidine.



But even those treatments have drawbacks. The inhaled drug Relenza can't be used in young children and some older patients also have trouble with it. And some strains of flu have also already shown resistance to Ramantadine. Doctors say this is yet another reason why your best bet at fighting the virus is to get a flu shot.



"The number one goal in dealing with influenza is to prevent becoming ill in the first place and vaccination is the best way to do that. Even now it is not too late to get vaccinated," said Moscona.