The U.S. Food and Drug Administration (FDA), the American counterpart to the Saudi Food and Drug Authority (SFDA), together with GlaxoSmithKline informed healthcare professionals of changes to the WARNINGS AND PRECAUTIONS sections of prescribing information for Zanamivir, marketed as Relenza.

Zanamivir was approved in Saudi Arabia in 2004 for the treatment and prophylaxis of influenza virus. It is an inhibitor of influenza virus neuraminidase affecting release of viral particles.

This action was based on information from postmarketing reports (mostly from Japan) which included events as delirium and abnormal behavior leading to injury in patients with influenza who are receiving neuraminidase inhibitors, including Relenza.

These events were reported primarily among pediatric patients and often had an abrupt onset and rapid resolution. The contribution of Relenza to these events has not been established. Influenza can be associated with a variety of neurologic and behavioral symptoms which can include seizures, hallucinations, delirium, and abnormal behavior, in some cases resulting in fatal outcomes. These events may occur in the setting of encephalitis or encephalopathy but can occur without obvious severe disease.

ACTIONS THAT PUBLIC AND HEALTHCARE PROFESSIONALS SHOULD FOLLOW:

• Patients with influenza should be closely monitored for signs of abnormal behavior. If neuropsychiatric symptoms occur, the risks and benefits of continuing treatment should be evaluated for each patient.

REPORT ADVERSE DRUG REACTIONS TO THE SFDA
The public and health professionals are encouraged to report adverse drug reactions to the National Pharmacovigilance center on the internet at: