WASHINGTON - The most widely used flu drug in the world should carry a stronger warning label about psychiatric problems seen in a handful of patients, government advisers said Tuesday.
A panel of experts to the Food and Drug Administration recommended drug maker Roche change the warning label for Tamiflu, which has been used by 48 million patients since its launch in 1999.
The drug's label already mentions reports of delirium and self-injury, primarily among children in Japan, but some FDA's experts suggested the language should mention several patients died as a result of these abnormal behaviors. The panel was discussing specifics of the language late Tuesday.
While FDA's advisers agreed stronger warnings were needed, they said that it is unclear whether the psychiatric problems are a side effect of the drug or the flu itself. Some panelists said labeling should point out that similar deaths have also occurred in flu patients not on medication.
Nearly 600 cases of psychiatric problems have been reported in Tamiflu patients, with 75 percent of them coming from Japan. Five children there have died after "falling from windows or balconies or running into traffic," according to FDA.
Japan accounts for two thirds of the $2.4 billion global market for Tamiflu because doctors there almost always prescribe drugs to treat flu symptoms.
Japanese health authorities are scheduled to hold their own meeting on Tamiflu's safety next month.
Basel, Switzerland-based Roche on Tuesday presented its own analysis of more than 150,000 patients that showed no connection between Tamiflu and increased risk of psychiatric problems.
"Over the last year we've been looking at a variety of data and undertaken additional studies that so far have shown no causality between Tamiflu and these events," Glaxo product director David Reddy said in an interview Tuesday. "In fact, the data increasingly points to the role of influenza in these events."
