The labeling for Relenza (zanamivir inhalation powder, from GlaxoSmithKline) has been revised to include a warning of neuropsychiatric events. In post-marketing clinical use, there have been reports of delirium and abnormal behavior leading to injury of influenza patients who are receiving neuraminidase inhibitors, including Relenza. These events were reported primarily among pediatric patients and often had an abrupt onset and rapid resolution. Based on these reports, patients on Relenza should be monitored for signs of abnormal behavior. If neuropsychiatric symptoms occur, the risks and benefits of continuing treatment should be evaluated for each patient.

Relenza is indicated for treatment of uncomplicated acute illness due to influenza A and B virus in adults and pediatric patients ≥7 years of age who have been symptomatic for no more than 2 days.

For more information call (888) 825-5249 or visit www.fda.gov/medwatch/safety/2008/safety08.htm#Relenza.