Tests show Tamiflu ineffective

January 9, 2009 3:38:18 PM PST
A few weeks ago, Action News told you doctors saw the first signs that the drug Tamiflu wasn't working to help treat this year's primary flu strain. Now comes word that it's almost completely resistant.

Tamiflu didn't work with 99-percent of flu samples tested.

That's compared to 11-percent resistance last year.

Doctors say the mutation creating the resistance looks spontaneous and not the result of overuse.

They can't, however, explain why the mutation occurred.

Federal health officials say another drug, Relenza, is working well.