by: David Gutierrez
An FDA advisory panel has recommended stronger warnings on two influenza drugs after reviewing evidence linking them to neurological and psychiatric problems that have led to deaths in some cases.
The current warning on Roche Laboratories’ Tamiflu (generic name oseltamivir) urges close monitoring of flu patients, particularly children, for “increased risk of self injury and confusion shortly after taking Tamiflu.” The panel recommended that this warning be strengthened to say that “in some cases, these behaviors resulted in serious injuries, including death, in adult and pediatric patients.”
The label of Glaxo SmithKline’s Relenza (generic name zanamivir), the panel said, should be strengthened to mention “reports of hallucinations, delirium and abnormal behavior.” The panel said that both labels should mention that some flu patients not taking the drugs have also experienced such symptoms.
There have been no reported deaths from Tamiflu in the United States, but in Japan, where the drug is much more widely used, at least 14 deaths have been reported. Five children under the age of 17 died after “falling from windows or balconies or running into traffic,” according to the FDA. According to Roche, two people under the age of 21 died from a brain infection, and seven deaths from neuropsychiatric symptoms have also been attributed to use of the drug by adults.
Since Tamiflu’s introduction in 1999, a total of 48 million prescriptions have been written, 75 percent of them in Japan. According to Roche, 1,745 of 1,808 reports of side effects came from Japan.
The FDA has noted that people in Japan appear to be more likely to report side effects than people in the United States.
In March, Japan issued a warning against prescribing Tamiflu to people between the ages of 10 and 19, and South Korea followed suit a month later with a warning against use by teenagers.