Advisers say current labeling doesn't reflect reports of bizarre behaviors and sudden deaths
TUESDAY, Nov. 27 (HealthDay News) -- A U.S. Food and Drug Administration advisory panel recommended Tuesday that the prescription flu drug Tamiflu (oseltamivir) should have a stronger warning label to reflect reports of bizarre behaviors and deaths among children who use the medication.
The FDA's Pediatric Advisory Committee, in a 9-5 vote, said that drug maker Roche Holding AG should change its prescribing information because it doesn't adequately explain side effects reported by hundreds of patients in Japan and the United States, according to Bloomberg News.
The drug's label mentions reports of delirium and self-injury, primarily among children in Japan, but the advisory panel said the language should state that several patients died as a result of these behaviors, the Associated Press reported.
In addition, the panel recommended that labeling for the flu drug Relenza, (zanamivir), should also reflect reports of abnormal behavior, according to Bloomberg.
The FDA is not obliged to follow its expert panels' recommendation, but it usually does. A safety review released Friday by the FDA's Division of Antiviral Products urged stronger label warnings for both drugs, including stricter monitoring of children taking these drugs.
According to the FDA safety review, there have been 596 reported cases of psychiatric behavior associated with Tamiflu use. Most of these cases happened among patients aged 21 or younger. The majority (75 percent) occurred in Japan.
Fifty-nine of the cases were classified as delirium with impulsive behavior and self-injury. Delirium, delusions, hallucinations or psychosis accounted for another 225 cases. In total, five children died "as a result of falls from windows or balconies or running into traffic," the safety review found, and three adults committed suicide. So far, there haven't been any such cases reported in the United States, according to the FDA.
The FDA safety review also reported that in cases involving Relenza, mostly in Japan, there have been 115 reports of "delirium with impulsive behavior and self-injury in which the patient expressed 'fear' and attempted to flee or expressed a desire to 'jump,'" the agency said. There were no deaths associated with Relenza.
During its meeting on Tuesday, the advisory panel said it was unclear whether the psychiatric problems are a side effect of Tamiflu or the flu itself, AP reported.
At the hearing, representatives of Roche told the panelists that the flu itself, not Tamiflu, caused the bizarre behaviors.
"We feel that the current U.S. prescribing information is an accurate assessment of the current data," Jonathan Solsky, Roche's director of drug safety risk management, testified, according to Bloomberg.
In a statement released after the meeting, Roche reiterated its faith in the drug. "According to data analyzed from two U.S. claims databases of more than 150,000 patients, there is no increased risk for neuropsychiatric events in influenza patients treated with Tamiflu compared to untreated influenza patients," the statement said.
The FDA first began reviewing Tamiflu in 2005. Since November 2006, the drug's label has had a warning focused on self-injury and delirium, advising that patients be monitored during treatment. In March, the Japanese Ministry of Health, Labor and Welfare limited Tamiflu use in patients aged 10 to 19 years old.
One expert believes a new warning is appropriate for Tamiflu. "The idea that there have been 596 neuropsychiatric events is a reason for the FDA to put a strong warning on the label," said Dr. Marc Siegel, a clinical associate professor of medicine at New York University School of Medicine in New York City.
But he is also concerned that the public might overreact.
"I am not a fan of replacing fear of a disease with fear of the treatment for the disease," said Siegel, speaking before the advisory panel met. "You don't need to go from one panic to another."
Tamiflu is overused, however, Siegel added. "It's supposed to be used in a very narrow window, and I am not surprised that there have been psychiatric side effects related to this drug," he said. "Maybe the new warning will lead to less overuse."
Tamiflu is approved both as a preventive and a treatment for flu for adults and children aged 1 year and older.
Relenza is approved as both a flu preventive and a treatment in adults and children aged 5 years old and older.
GlaxoSmithKline, the British maker of Relenza, doesn't believe the label needs changing. "The review and analysis of all the information available in this safety summary of neuropsychiatric events does not implicate or indicate a significant causal role of zanamivir. Therefore, no revisions are warranted for the U.S. Prescribing Information and the FDA-approved Patient Labeling for Relenza," the company told the FDA.
For more on the flu, visit the U.S. Centers for Disease Control and Prevention.
SOURCES: Marc Siegel, M.D., clinical associate professor, medicine, New York University School of Medicine, New York City; Pediatric Safety Update for Tamiflu, Division of Antiviral Products, U.S. Food and Drug Administration; statements, GlaxoSmithKline and Hoffmann-La Roche Inc.; Bloomberg news; Associated Press
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