Tamiflu (Oseltamivir) Indications
Tamiflu is indicated for treatment of acute, uncomplicated influenza A and B in patients 2 weeks of age and older who have been symptomatic for no more than 48 hours, and for prophylaxis of influenza A and B in patients 1 year and older. 1
Treatment Indications
Primary Treatment Populations
Offer treatment as soon as possible to:
Children hospitalized with presumed or confirmed influenza - regardless of vaccination status or time since symptom onset 2, 3
Children with severe, complicated, or progressive illness attributable to influenza - including those requiring mechanical ventilation or with baseline oxygen requirements 2
Children at high risk of complications - this includes those younger than 2 years (especially under 6 months), those with chronic medical conditions (cardiac, pulmonary, metabolic, neurologic, renal, hepatic, hematologic disorders), immunocompromised states, or compromised respiratory function 2
Secondary Treatment Populations
Consider treatment for:
Any otherwise healthy child with presumed influenza - particularly if they can be treated within 48 hours of symptom onset 2
Healthy children who live with high-risk household contacts - specifically those with siblings or household members younger than 6 months or with medical conditions predisposing to complications 2
Prophylaxis Indications
Oseltamivir is approved for prevention of influenza in patients 1 year and older 1:
Post-exposure prophylaxis: 75 mg once daily for 10 days in adults/adolescents (weight-based dosing in children 1-12 years) 1
Community outbreak prophylaxis: 75 mg once daily for up to 6 weeks in adults/adolescents (weight-based dosing in children 1-12 years) 1
Household prophylaxis: When administered within 48 hours of symptom onset in the infected household member 4
Age-Specific Approvals
The FDA has approved oseltamivir with specific age indications 1:
- Treatment: Approved for patients 2 weeks of age and older 1
- Prophylaxis: Approved for patients 1 year and older 1
The AAP supports off-label use in infants from birth (including preterm infants) for treatment because benefits outweigh risks in this high-risk population 2, 3
Critical Timing Considerations
Optimal efficacy requires initiation within 48 hours of symptom onset 1, 4
Treatment should NOT be delayed while awaiting diagnostic test results - clinical judgment based on local influenza activity and patient risk factors should guide empiric treatment 2
Treatment initiated after 48 hours may still provide benefit in hospitalized patients or those with severe, complicated, or progressive disease 2, 5
Important Limitations of Use
Oseltamivir is NOT:
A substitute for annual influenza vaccination - vaccination remains the primary prevention strategy 1
Recommended for patients with end-stage renal disease not undergoing dialysis - dose adjustments are required for renal impairment 1
Universally effective - clinicians should consider available information on influenza drug susceptibility patterns and treatment effects when deciding whether to use 1
Clinical Pitfalls
Do not withhold treatment from high-risk or hospitalized patients based on negative rapid influenza tests - these have suboptimal sensitivity and false-negative results are common 2
Do not delay treatment to obtain specific diagnostic confirmation - molecular assays or PCR are preferred in hospitalized patients but should not delay empiric therapy 2
Vomiting (the most common side effect) occurs in approximately 15% of treated children versus 9% receiving placebo - this can be minimized by taking oseltamivir with food 2, 4