Docs struggle with drug-resistant flu

The drug-resistance of the widely circulating type A H1N1 flu virus highlights the need for new flu drugs and faster tests, U.S. researchers said.

Type A H1N1 is resistant to Tamiflu, the anti-viral that until now been the first choice for treating both seasonal flu and bird flu, USA Today reported Monday. Tamiflu is still effective against most cases of bird flu, the report said.

Doctors still have options for treating type A H1N1 influenza. Relenza, also known as zanamavir, is in the same class as Tamiflu but the inhaled powder is difficult for some people to use. Older anti-virals, amantadine and rimantadine, will also work against that particular strain. The problem is that doctors don’t often know which flu strain is making their patient ill. The other two common flu viruses this season, type A H3N2 and type B, are not resistant to Tamiflu but H3N2 is resistant to amantadine and rimantadine and won’t work against type B flu.

Rapid flu diagnostic tests can’t identify type A subtypes and a viral culture test takes nearly a week to identify the flu type, USA Today said.