The authors of the second study reviewed all available research on Tamiflu and Relenza, and concluded that healthy adults who took the drugs for four weeks or longer were less likely to be stricken with symptoms of flu, although the drugs did not prevent people from actually becoming infected with the virus.
"They prevent the newly formed viruses from leaving the infected cells but they don't prevent initial virus from getting into the body," said study author Dr. Nayer Khazeni, an instructor of medicine in the division of pulmonary and critical care medicine at Stanford University Medical Center.
The two drugs appeared to be equally effective, although patients taking Tamiflu experienced more nausea and vomiting, especially if given in higher-than-recommended doses.
Also, the authors noted, many groups have just never been studied in this context, including children under the age of 12, immune-compromised individuals and people who have received the nasal flu vaccine.
"Another finding was that all of the studies were sponsored by makers of the drugs, which is not surprising," Khazeni said. "They were good quality, but it's always nice to see an independent evaluation."
Although governments have stockpiled these two drugs to use during a pandemic, it's unclear what role the drugs play currently in the swine flu pandemic.
"It's not clear if there's a role for extended use of prophylactic medications," Khazeni said. "Some groups are targeted for extended-duration antiviral prophylaxis, such as high-risk groups and first-line health-care workers."
But these plans are for a more severe pandemic setting, she added.
All rights reserved