For additional information see Neuraminidase inhibitors
HIDE CLASS
Mode of action from Neuraminidase inhibitors
Reduce influenza virus replication by inhibiting the viral surface enzyme neuraminidase, preventing release of new virus from cells.
Treatment of infections due to influenza A and B virus in selected people, see Use in influenza
Prevention of influenza
Indications from Neuraminidase inhibitors
Influenza A and B
Hereditary fructose intolerance—oral liquid contains approximately 0.9 g sorbitol with each 30 mg oseltamivir.
Reduce dose if CrCl <60 mL/minute.
Data for use in children <1 year for the prevention of influenza are limited; consider using oseltamivir only in a pandemic.
Precautions from Neuraminidase inhibitors
Oseltamivir and zanamivir are considered safe to use; avoid peramivir as data are limited.
Oseltamivir and zanamivir are considered safe to use; no data for peramivir but unlikely to be absorbed by child.
nausea, vomiting (usually for first 1–2 days), headache
GI bleeding, haemorrhagic colitis, hepatitis and increased liver enzymes in patients with influenza-like illness
Adverse effects from Neuraminidase inhibitors
Neuraminidase inhibitors are generally well tolerated.
allergy (including rash, anaphylactic/anaphylactoid reactions, angioedema), serious skin reactions (eg Stevens-Johnson syndrome, erythema multiforme)
Symptoms including abnormal behaviour, hallucinations and delirium have rarely been described (mainly in children and with oseltamivir use).
Influenza can also cause neuropsychiatric symptoms; evidence for oseltamivir is conflicting and the link with peramivir and zanamivir is unclear.
The earlier treatment starts, the shorter and less severe the illness. Start within 48 hours (ideally within 24 hours) after onset of symptoms (however, in severe illness, later treatment, eg within 4 days of onset, is still of benefit).
Oral, 75 mg twice daily for 5 days.
CrCl 30–60 mL/minute, oral 30 mg twice daily for 5 days.
CrCl 10–30 mL/minute, oral 30 mg once daily for 5 days.
<15 kg, oral 30 mg twice daily for 5 days.
15–23 kg, oral 45 mg twice daily for 5 days.
23–40 kg, oral 60 mg twice daily for 5 days.
Oral, 3 mg/kg twice daily for 5 days.
Begin treatment within 2 days of exposure (close contact with an infected person).
Oral, 75 mg once daily for 10 days (has been taken daily for 6 weeks in community outbreaks).
CrCl 30–60 mL/minute, oral 30 mg once daily for 10 days.
CrCl 10–30 mL/minute, oral 30 mg on alternate days for 10 days.
<15 kg, oral 30 mg once daily for 10 days.
15–23 kg, oral 45 mg once daily for 10 days.
23–40 kg, oral 60 mg once daily for 10 days.
Oral, 3 mg/kg once daily for 10 days.
A 15 mg/mL oseltamivir liquid can be made before each dose by asking the carer to:
mix the contents of one 75 mg capsule in 5 mL water by stirring for about 2 minutes
draw the correct dose volume into a syringe (discard unwanted liquid)
mix the dose in soft food to disguise the taste before giving it.
Nausea and vomiting in the first couple of days is common with this medicine; take it with food to help reduce this. If swallowing capsules is difficult, you can take the contents of the capsule mixed in soft food, eg yoghurt, honey.
Counselling from Neuraminidase inhibitors
Treatment: this medicine is intended to shorten the time you have symptoms, such as fever, headache, sore muscles, cough and sore throat.
Prevention: you may get flu even if you are taking this medicine.
Practice points from Neuraminidase inhibitors
otherwise healthy people should treat uncomplicated influenza by resting, drinking plenty of fluids and using paracetamol for symptom relief
neuraminidase inhibitors have no effect in treating or preventing influenza-like illness
in immunocompromised or severely ill people, a longer treatment duration (eg up to 10 days with oseltamivir) may be considered
be aware of circulating influenza virus strains and their resistance patterns as susceptibility to antivirals changes rapidly
cap, 30 mg, 10, Tamiflu
cap, 45 mg, 10, Tamiflu
cap, 75 mg, 10, Talminex, Tamiflu
oral liquid, 6 mg/mL, 65 mL (powder), 1, Tamiflu