Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Effectiveness: The benefit of oseltamivir has not been evaluated for the treatment of flu symptoms that have been present for more than 2 days.
Flu shots: Oseltamivir is not a substitute for the flu shot. Continue to receive an annual flu shot as advised by your doctor.
Kidney function: Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: Oseltamivir may also cause decreased liver function, and liver failure in rare cases. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.
Neurological effects: There have been rare reports of people who have experienced neurological and psychological problems while taking oseltamivir. These included hallucinations, delusions, delirium, abnormal behaviour, and self-injury. If you experience any of these symptoms, seek immediate medical attention. If you have any concerns about this medication, contact your doctor.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if oseltamivir passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding. Mothers who are breast-feeding children under one year old should not take this medication.
Children: The safety and effectiveness of using this medication have not been established for children under one year of age.