British scientists say there isn't enough evidence to prove the antiviral drug Tamiflu reduces the spread of flu.
The findings published Thursday in the journal BMJ question whether governments worldwide were justified in spending millions on the drug during the 2009 swine flu pandemic.
Researchers at the Cochrane Collaboration and BMJ have long argued there weren't enough trials to prove Tamiflu works and say after getting access to internal trials conducted by its maker, Roche AG, they found Tamiflu reduces flu symptoms by about a half a day in adults but has little effect in children. Compared to people taking a placebo pill, there was no proof people taking Tamiflu were less likely to be hospitalized or suffer serious flu complications.
Experts not involved in the research pointed out that Tamiflu works best when given early and that it's hard for doctors to catch people at that stage.
"It's not that the drugs don't work, it's just difficult to use them to their best effect," said Wendy Barclay, an influenza expert at Imperial College London, in a statement. She cited some problems with the way scientists at the Cochrane group and BMJ interpreted the data and said it was wise of governments to stockpile Tamiflu since there are few drugs available to treat flu. "If another pandemic came tomorrow and the (U.K.) government had no drug with which to treat thousands of (flu) patients, I imagine there would be a public outcry."
Swiss pharmaceutical Roche said they "fundamentally disagree" with the overall conclusions of the BMJ series and said more than 100 countries have approved Tamiflu worldwide. The U.S. spent more than $1.3 billion on its antiviral stockpile while Britain spent nearly $711 million on Tamiflu in its pandemic preparations, according to government documents cited by the Cochrane group and BMJ.
Public health agencies including the World Health Organization and the U.S. Centers for Disease Control and Prevention continue to recommend Tamiflu be used to treat flu and say it has proven helpful in treating patients with novel strains like bird flu.
o;mso-m?; nb??b ?c :auto; mso-line-height-alt:9.4pt;background:white'>One year after treatment, 19 percent of the surgery patients but only 14 percent of those given a CoreValve had died.
Stroke rates also seemed lower, though this was not one of the main results researchers were tracking. After one year, 13 percent of surgery patients and 9 percent of the others had had a stroke.
Two-year follow-up is not complete, but "we are certainly encouraged" that trends appear to be continuing, said one of the study's leaders, Dr. David Adams of New York's Mount Sinai Hospital.
There were drawbacks to the CoreValve, though — twice as many patients needed pacemakers afterward. Other complications were a tradeoff — more vascular problems with the CoreValve but more problems with a fluttering heartbeat called atrial fibrillation among those who had surgery.
Still, several independent experts praised the results.
"It's a great leap forward" for fixing valves through blood vessels, said Dr. David Kandzari of Piedmont Heart Institute in Atlanta.
The study was paid for by Medtronic, and many study leaders consult for Medtronic, Edwards or other heart device makers. Results also were published online by the New England Journal of Medicine.
Doctors say both companies' artificial valves need more long-term study to see if they hold up as well as the ones implanted surgically, which typically last 20 years. Other firms are also testing catheter-placed valves.