Neuraminidase inhibitor
Oseltamivir
Brand names: Tamiflu
Adult dose
Dose: Treatment: 75mg PO BD for 5 days. Prophylaxis: 75mg OD for 10 days
Route: PO
Frequency: BD or OD
Paediatric dose
Route: PO
Frequency: BD
Age bands
- 0–12m: 3 mg/kg BD
- 12–216m: weight-based: ≤15kg 30mg, 15–23kg 45mg, 23–40kg 60mg, >40kg 75mg BD
Dose adjustments
Renal
Mandatory — refer to BNF
Clinical pearls
- Influenza A and B; start within 48h of symptoms
- Per UK Health Security Agency / NICE TA168/TA158 — at-risk groups in declared influenza period
Contraindications
- Hypersensitivity
Side effects
- Nausea/vomiting
- Headache
- Neuropsychiatric events (rare — children/adolescents)
- Hepatotoxicity
- Skin reactions
Interactions
- No clinically significant; reduce if eGFR <60
Monitoring
- Symptom resolution
- Mental state in young patients
Reference: BNFc; BNF; NICE TA168/TA158; UKHSA; https://bnf.nice.org.uk/drugs/oseltamivir/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
- SMART Risk Score for Recurrent CVD · Cardiovascular Risk
- PCSK9 Inhibitor Eligibility Assessment · Lipid Management
- Immune-Related Adverse Events (irAE) -- GI Toxicity Colitis Grading · Oncology-Related GI
- irAE Hepatitis Grading (CTCAE) · Immunotherapy
- DIPSS — Dynamic International Prognostic Scoring System for Myelofibrosis · Cancer Prognosis
- BALL Score for Relapsed/Refractory CLL · Leukaemia
Pathways
- Infective Endocarditis · ESC 2023 Infective Endocarditis Guidelines; NICE NG41
- Eczema Herpeticum · BAD; NICE CKS
- Suspected Bacterial Meningitis (Adult) · NICE NG240 (2024); NICE NG143 (paeds)
- Clostridioides difficile Colitis · NICE NG199 (2021); IDSA/SHEA 2021
- Returning Traveller — Fever · NaTHNaC; PHE; ESCMID 2018
- Malaria — Diagnosis & Management · PHE 2016; WHO 2023