Americans hoarded Tamiflu last fall, according to a new report that suggests some may have been trying to protect their children.

The number of prescriptions that were filled for the antiviral medication rose nearly five-fold between fall 2004 and the same period in 2005, according to researchers at the U.S. Centers for Disease Control.

Tamiflu, which is recommended during the first 24 hours of flu symptoms, is one of the few medications believed to be effective against bird flu.
(Ed Wray/Associated Press)

Prescriptions jumped from 27.3 prescriptions per 100,000 in 2004 to 133.6 per 100,000 the following year, the analysis of drug claims from the U.S. health claims processing company, Medco, found.

Given that there were so few cases of illness during the time period and that Tamiflu is recommended during the first 24 hours after flu symptoms appear, it is likely the prescriptions were intended for stockpiles, not treatment, the researchers said.

In 2005, the highest prescription rates were among people aged 50 to 64, even though seniors experience more influenza disease annually.

There was also a seven-fold increase in Tamiflu prescriptions for children under 18 from 2004 to 2005, including infants — even though the drug is not approved for those under 12 months.

Spike matches media coverage

"The correlation between the heightened U.S. media coverage around Tamiflu and the prescription activity for the drug between September and November in 2005 is uncanny," said Dr. Robert Epstein, Medco's chief medical officer and co-author of the presentation to the annual meeting of the Infectious Diseases Society of America.

The study included only U.S. data, but data compiled by IMS Health shows Canadian sales of Tamiflu showed a similar pattern last year.

Among physicians surveyed, 17 per cent reported having stockpiles of the drug. Older, more experienced doctors, regardless of specialty, also prescribed more Tamiflu compared with younger, more recently trained physicians.

Pandemic plans

A second flu study published in the October issue of the journal PloS Medicine found one-third of countries that have drafted flu pandemic plans have failed to describe how treatment would be distributed.

"Because of costs and the time delay of manufacturing strain-specific vaccines, critical medical resources are likely to be scarce in a pandemic and will require rationing," said Lori Uscher-Pines, lead author of the study and a doctoral candidate in the Bloomberg School of Public Health in Baltimore, Md.

"However, we learned that individual countries have not consistently prioritized population groups for vaccines and antivirals. No countries prioritized population groups to receive ventilators, face masks and other critical resources."

Canada's plan prioritized health-care workers on the grounds they perform an essential service and reduce death and disease, but excluded children saying they have a lower risk of severe outcomes in annual flu outbreaks and don't harm the economy the same way adults do if ill.

Countries without an allocation plan included the U.S., Norway, Australia, India, China, Serbia, Bahrain, Israel, South Africa, U.K., Mexico, Venezuela, Hong Kong, Thailand and Singapore.

Almost half of the plans prioritized antivirals such as Tamiflu while 62 per cent emphasized giving people a flu vaccine, but antivirals may be the first line of defence in a pandemic, the researchers said.

With files from the Canadian Press