"It's generally known that the evidence for prevention of flu complications is weak," said Dr. Marvin Bittner of Creighton University in Omaha.
Dr. Amy Kaji of the University of California Los Angeles said she and her colleagues don't recommend the drug for otherwise healthy adults.
"I think we have all known this data that Tamiflu reduces symptomatology, at best, by one day," she said in an email. "The news is therefore not very new."
On the other hand, she said, in severely ill patients admitted for pneumonia and an influenza-like-illness, "there is some evidence demonstrating benefit."
Dr. Kristi Koenig of the University of California Irvine said she's seeing many otherwise healthy adults with flu-like symptoms who are worried about the H1N1 pandemic flu.
"They should understand that Tamiflu may not be indicated for them," Koenig said. "The vast majority of young healthy adults will do well with rest, fluids and ibuprofen/Tylenol, without tamiflu."
But it's a question of perspective, said Dr. William Schaffner of Vanderbilt University. "The drug is not perfect," he said in a telephone interview, but it offers at least some benefit for some people.
He said the Cochrane reviewers, while ethical and well-meaning, can sometimes be "extraordinarily prissy" about what kinds of data they'll accept.
"They're a lot more critical of some of the data than I would be," he said.
The U.S. Centers for Disease Control and Prevention doesn't comment on papers before they're published, a CDC spokesman said. But the spokesman said the agency's position has not changed from last month when Dr. Tim Uyeki of the agency's influenza division, wrote that observations suggested a benefit for the drug in reducing complications at least in some patients.
"Evidence from observational studies supports the benefit of neuraminidase inhibitors (oseltamivir or zanamivir) in reducing complications, including deaths, among hospitalized patients with 2009 pandemic influenza A (H1N1)," Uyeki wrote in the New England Journal of Medicine.
Many experts cautioned that the Cochrane review should not be taken to apply to all people with flu.
"It is important not to extend these findings to high-risk individuals or people with severe illness for whom antiviral drugs are recommended," said Besser.
"In these people, even a small benefit may be worth it," he said.