Some Flu Viruses Resist Drugs

Japanese Scientists Find Flu Virus That Resists Tamiflu, Relenza
By Miranda Hitti WebMD Medical News
Reviewed by Louise Chang, MD
April 3, 2007 -- Some flu viruses appear to resist the antiviral flu drugs Tamiflu and Relenza, report Japanese researchers.
They included Shuji Hatakeyama, MD, PhD, a virus expert at the University of Tokyo.
Hatakeyama and colleagues had previously noted cases of influenza type A that resisted Tamiflu. Now, they note cases of influenza type B that show reduced sensitivity to Tamiflu and Relenza.
Hatakeyama's team studied flu viruses from a Japanese epidemic of influenza type B from 2004 to 2005.
The flu specimens came from patients including 74 children who took Tamiflu for five days, 282 untreated children, and 66 untreated adults.
One of the children who took Tamiflu had influenza type B that resisted Tamiflu and Relenza, according to the researchers' lab tests.
Seven untreated patients had influenza type B that resisted Tamiflu and Relenza, the study shows.