What is the known adverse reaction for which a client taking oseltamivir for influenza infection should seek emergency medical assistance?

Seizures are a known serious adverse reaction associated with the use of oseltamivir, particularly in certain populations, such as pediatric patients. This reaction can indicate severe neurological impairment and requires immediate medical attention. While other side effects like headache, nausea, and fatigue are common and typically mild, seizures represent a significant medical emergency that could lead to more severe complications if not addressed quickly. Therefore, clients taking oseltamivir should be vigilant for any signs of seizures and seek emergency assistance if they occur. Recognizing this serious adverse reaction is important for ensuring patient safety during antiviral treatment for influenza.