Report Questions Effectiveness of Flu Meds
'Hidden' trial data reveals that some Tamiflu claims were unfounded, researchers say
By Margaret Farley Steele
THURSDAY, April 10, 2014 (HealthDay News) -- No evidence exists to show that anti-flu medicines stockpiled by countries around the world protect people from the spread of flu or reduce related hospitalizations and complications, a new analysis contends.
The report from the nonprofit Cochrane Collaboration urges world leaders who spend countless dollars on medications like Tamiflu and Relenza for use in an influenza pandemic to reconsider this practice.
The findings, published April 10 in the BMJ, come from an analysis of internal reports of 20 Tamiflu (oseltamivir) and 26 Relenza (zanamivir) trials that involved more than 24,000 people.
Taking one of these drugs may reduce flu symptoms in adults by less than a day compared to taking an inactive placebo, the researchers found. However, they said claims that the drugs -- known as neuraminidase inhibitors -- curb flu transmission or reduce complications such as pneumonia are unfounded.
"We now have the most robust, comprehensive review on neuraminidase inhibitors that exists," said Dr. David Tovey, Cochrane editor-in-chief, in a news release from the research network.
"Initially thought to reduce hospitalizations and serious complications from influenza, the review highlights that Tamiflu is not proven to do this, and it also seems to lead to harmful effects that were not fully reported in the original publications," Tovey added.
Those side effects include headache, nausea and vomiting, the new study said. Some trials also noted an increased risk of psychiatric disturbances and kidney problems.
Evidence from the trials and studies reviewed showed that Tamiflu and Relenza alleviated flu-like symptoms in adults about half a day faster than in those taking a placebo. But the researchers found no proof that Tamiflu stopped someone infected with flu from transmitting it to others or that it prevented hospitalizations.
Nor was there evidence that the drugs lessened the odds of developing flu-related pneumonia, sinus problems or middle-ear infections in adults, researchers said.
Use of Tamiflu soared worldwide after the H1N1 "swine flu" pandemic of 2009, and governments began stockpiling the antivirals at great cost hoping to prevent widespread illness or deaths. The World Health Organization considers it an "essential" medication.
The United States has spent more than $1.3 billion building a reserve supply of antivirals, according to published reports.
"We need better antivirals, including combination antiviral treatments, but right now this is all we have got," said Dr. Tim Uyeki of the U.S. Centers for Disease Control and Prevention's flu division, according to an NBC News report.
"CDC recommends early antiviral treatment as soon as possible for any hospitalized patient with suspected or confirmed influenza," he added. "The number of observational studies suggesting the benefit of early antiviral treatment in hospitalized patients keeps growing."