A University of British Columbia professor who specializes in researching publicly approved medicines is casting doubt on the effectiveness of the anti-pandemic drug Tamiflu.

Dr. Barbara Mintzes says she's looked at the manufacturer's own clinical research and found that Tamiflu's beneficial effects have been significantly overstated by the manufacturer Roche.

"You get the impression it's effective against complications of the flu," Mintzes said. "Really, it's a case of cherry-picking some of the results."

Mintzes said her analysis of the manufacturer's research shows the drug has no effect on flu complications — one of the main reason governments stockpile it.

At best, she said, Tamiflu only shortens flu symptoms by a day.

"Between people who were taking Tamiflu and people who were taking a placebo or sugar pill…there wasn't any reliable evidence of a reduction in flu complications," she said.

Medical officer disagrees

However, B.C.'s chief medical health officer, Dr. Perry Kendall, disagreed.

Kendall said he has compared hosptilization rates with and without Tamiflu during the 2009 H1N1 pandemic.

"By targeting Tamiflu to people who were potentially at risk of serious complications, it did reduce the complications rate and the amount of hospitalization."

Kendall did agree, however, that Tamiflu should be subjected to more research.

The flu treatment has been subject to criticism before by other research also questioning its effectiveness.

With files from the CBC's Frederic Zalac