Antiviral Drug Labels Get Warnings for Neuropsychiatric Changes

Yael Waknine


March 04, 2008

March 4, 2008 — The safety labeling for oseltamivir phosphate (Tamiflu, Roche Laboratories Inc) has been revised to include stronger warnings regarding the risk for neuropsychiatric adverse events, the US Food and Drug Administration (FDA) warned healthcare professionals today. The revisions were the result of recommendations made by the agency's Pediatric Advisory Committee meeting held in November 2007.

GlaxoSmithKline Plc has also added a warning to the label of zanamivir (Relenza) for neuropsychiatric adverse events, as reported by Reuters Health.

Symptoms of delirium and abnormal behavior leading to sometimes fatal self-injury have been reported with use of oseltamivir for the treatment of influenza, primarily in Japan, according to an alert issued by MedWatch, the FDA's safety information and adverse event reporting program. These events occurred primarily among pediatric patients and were often abrupt in onset and resolution.

Although a causal role for the drug cannot be established because of the voluntary nature of the reporting, they appear to be uncommon according to oseltamivir usage data. Also, children and adolescents with influenza may be at increased risk for seizures, confusion, or abnormal behavior during the early stages of their illness even if it remains untreated.

Patients receiving oseltamivir should be closely monitored for signs of abnormal behavior throughout the treatment period. If neuropsychiatric symptoms occur, the risks and benefits of continued treatment should be evaluated.

Oseltamivir is indicated for the prophylaxis of influenza and the treatment of uncomplicated acute influenza of no more than 2 days' duration in patients aged 1 year and older.

Additional information regarding oseltamivir may be obtained by contacting the manufacturer's service center at 1-800-526-6367.

Adverse events potentially related to oseltamivir therapy should be reported to the FDA's MedWatch reporting program by telephone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, online at, or by mail to 5600 Fishers Lane, Rockville, MD 20852-9787.


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