Tamiflu saves lives of severely ill flu patients

Packets of Tamiflu tablets are stored in the Swiss Army Pharmacy in Ittigen near Bern August 10, 2009.

CHICAGO (Reuters) - Roche AG's antiviral drug Tamiflu helped prevent deaths from seasonal flu in severely ill patients who had chronic underlying health problems, Chinese researchers said on Sunday.

A study of 760 older, severely ill patients in Hong Kong found that Roche and Gilead Sciences Inc's drug Tamiflu cut the rate of death by 37 percent.

More than 60 percent of patients in the study had underlying chronic illnesses, and 78 percent had been hospitalized with complications from seasonal flu.

The study, done by researchers at the Chinese University of Hong Kong and presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy in San Francisco, suggests the drug can help save the lives of seriously ill flu patients, Dr David Reddy, who leads Roche's pandemic flu task force, said in a telephone briefing.

Known generically as oseltamivir, Tamiflu is one of two antiviral drugs that work well against H1N1 swine flu.

The study took place in two hospitals in Hong Kong between 2007 and 2008. About half the patients in the study got Tamiflu and half got no treatment. Death rates were about the same at both hospitals.

"In this study, Tamiflu improved the survival rate by reducing the rate of death by 37 percent in this high-risk group of patients with severe seasonal flu compared to no treatment," Reddy said.

The U.S. Centers for Disease Control and Prevention is recommending that the very old and people with chronic medical conditions should be treated with antiviral drugs -- either Tamiflu or GlaxoSmithKline and Biota's Relenza -- when they have flu-like symptoms.

Health officials caution against using either drug in otherwise healthy people who have moderate or mild flu symptoms, however, because of the fear of resistance. Influenza viruses very quickly change to put up a strong defense against antiviral drugs. Last year the seasonal H1N1 virus developed strong resistance to Tamiflu. Two older flu drugs, amantadine and rimantadine, now have very little effect against influenza viruses.

(Reporting by Julie Steenhuysen in Chicago; Editing by Maggie Fox and Eric Beech)