Indications: most effective for the treatment of influenza if started within a few hours of the onset of symptoms. they are licensed for use within 48 hours of the first symptoms. Oseltamivir can reduce the risk of complications from influenza in the elderly and in patients with chronic disease Oseltamivir are licensed for post-exposure prophylaxis of influenza when influenza is circulating in the community. Oseltamivir should be given within 48 hours of exposure to However, in patients with severe influenza or in those who are immunocompromised, antivirals may still be effective after this time if viral shedding continues [unlicensed use]. Also licensed for use in exceptional circumstances (e.g. when vaccination does not cover the infecting strain) to prevent influenza in an epidemic.

Contra-indications: in patients with known serious hypersensitivity to oseltamivir or any component of the product. Severe allergic reactions have included anaphylaxis and serious skin reactions including toxic epidermal necrolysis, Stevens-Johnson Syndrome, and .

Renal impairment for treatment, use 30 mg twice daily if eGFR 30–60 ml/minute/1.73 m2 (30 mg once daily if eGFR 10–30 ml/minute/1.73 m2). for prevention, use 30 mg once daily if eGFR 30–60 ml/minute/1.73 m2 (30 mg every 48 hours if eGFR 10-30 ml/minute/1.73 m2) avoid for treatment and prevention if eGFR less than 10 ml/minute/1.73 m2.

Pregnancy: use only if potential benefit outweighs risk (e.g. during a pandemic) amount probably too small to be harmful (use only if potential benefit outweighs risk) (e.g. during a pandemic)

Side Effects: nausea, vomiting, abdominal pain, dyspepsia, headache; less commonly arrhythmias, convulsions and altered consciousness (usually in children and adolescents), eczema, rash; rarely hepatitis, gastro-intestinal bleeding, neuropsychiatric disorders (usually in children and adolescents), thrombocytopenia, visual disturbances, Stevens-Johnson syndrome, toxic epidermal necrolysis.

Dose: Prevention of influenza: ADULT and CHILD over 13 years: 75 mg once daily for 10 days for post-exposure prophylaxis; for up to 6 weeks during an epidemic.

NEONATE: 2 mg/kg once daily for 10 days for post- exposure prophylaxis.

CHILD 1–3 months : (2.5 mg/kg once daily for 10 days for post–exposure prophylaxis.

3 months–1 year : 3 mg/kg once daily for 10 days for post-exposure prophylaxis.

1–13 years: body-weight 10–15 kg, 30 mg once daily for 10 days for post-exposure prophylaxis (for up to 6 weeks during an epidemic). body-weight 15–23 kg, 45 mg once daily for 10 days for post-exposure.

prophylaxis (for up to 6 weeks during an epidemic): body-weight 23–40 kg, 60 mg once daily for 10 days for post-exposure prophylaxis (for up to 6 weeks during an epidemic); body-weight over 40 kg, adult dose Treatment of influenza: ADULT and CHILD over 13 years: 75 mg every 12 hours for 5 days. NEONATE, 2 mg/kg

every 12 hours for 5 days; CHILD 1–3 months: 2.5 mg/kg

every 12 hours for 5 days.

3 months–1 year : 3 mg/kg every 12 hours for 5 days;

1–13 years, body-weight 10–15 kg, 30 mg every 12 hours

for 5 days, body-weight 15–23 kg, 45 mg every 12 hours

for 5 days, body-weight 23–40 kg, 60 mg every 12 hours

for 5 days, body-weight over 40 kg, adult dose

Note Not for use in children under 1 year of age unless there is a pandemic