Tamiflu

What is Tamiflu used for?

Tamiflu's active ingredient, oseltamivir, is a neuraminidase inhibitor antiviral that blocks influenza virus replication and spread in the body. Starting it within 48 hours of symptom onset can shorten the illness and reduce its severity; it can also be used as prophylaxis for high-risk contacts. It has no effect on the common cold, which is caused by different viruses.

How to take Tamiflu and adjust the dose

Treatment: typical adult/adolescent (13+) dose is 75mg twice daily for 5 days. Prophylaxis: typically 75mg once daily for at least 10 days, depending on exposure and doctor's advice. Paediatric dosing is weight-based and must be set by a doctor. Dose adjustment is needed for reduced kidney function — consult a doctor. Can be taken with or without food, though taking it with food may reduce stomach upset. (This is a general adult reference dose — paediatric and special-population dosing varies considerably, so always follow your doctor's prescription.)

Tamiflu side effects

• Common: nausea, vomiting, headache, diarrhoea (vomiting more common in young children, diarrhoea more common in infants)
• Serious (rare): severe allergic reactions/anaphylaxis, severe skin reactions, neuropsychiatric events (confusion, abnormal behaviour — a particular concern in children/adolescents, though recent research suggests influenza itself can also cause these symptoms)

Who should not take Tamiflu?

• Contraindicated in those with serious hypersensitivity to oseltamivir or its components
• Dose adjustment needed with impaired kidney function — consult a doctor
• Use in pregnancy/breastfeeding only after a doctor weighs risks and benefits
• Patients (especially children/adolescents) should be monitored closely for abnormal behaviour or altered consciousness during treatment and seek prompt medical attention if this occurs
• Most effective when started within 48 hours of flu symptom onset — effectiveness declines after that window