What is the dose of Tamiflu (oseltamivir) for someone with known exposure to influenza?

Tamiflu (Oseltamivir) Dosing for Post-Exposure Prophylaxis

For adults and adolescents ≥13 years with known influenza exposure, administer oseltamivir 75 mg orally once daily for 10 days, starting within 48 hours of contact with an infected individual. 1, 2

Adult and Adolescent Dosing (≥13 years)

• Standard prophylaxis dose: 75 mg once daily for 10 days following close contact with an infected person 1, 2
• Initiate treatment within 48 hours of exposure for optimal effectiveness 1
• For seasonal prophylaxis during a community outbreak, the same dose (75 mg once daily) can be continued for up to 6 weeks 2
• In immunocompromised patients, prophylaxis may be extended up to 12 weeks 2

Pediatric Dosing (1-12 years)

Use the same weight-based doses as treatment, but administer once daily instead of twice daily for 10 days: 1

• ≤15 kg (≤33 lb): 30 mg once daily (5 mL oral suspension) 3, 1
• >15-23 kg (>33-51 lb): 45 mg once daily (7.5 mL oral suspension) 3, 1
• >23-40 kg (>51-88 lb): 60 mg once daily (10 mL oral suspension) 3, 1
• >40 kg (>88 lb): 75 mg once daily (12.5 mL oral suspension) 1

Infant Dosing (3-11 months)

• 3-11 months: 3 mg/kg once daily for 10 days 1
• Prophylaxis is NOT recommended for infants <3 months unless the situation is judged critical due to limited safety data 4

Renal Impairment Adjustments

For patients with creatinine clearance 10-30 mL/min: 1, 4

• Prophylaxis dose: 30 mg once daily for 10 days, OR
• Alternative: 75 mg every other day for 10 days (5 total doses) 1

Administration Considerations

• Can be taken with or without food, though taking with food may reduce gastrointestinal side effects (nausea/vomiting) 4, 2
• Available as capsules (30 mg, 45 mg, 75 mg) or oral suspension (6 mg/mL when reconstituted) 1
• For patients unable to swallow capsules, use the oral suspension or open capsules and mix contents with liquid 4

Critical Timing and Drug Interaction

• Must initiate within 48 hours of exposure to the infected individual for post-exposure prophylaxis 1, 2
• Avoid live attenuated influenza vaccine (LAIV) within 48 hours before starting oseltamivir, and do not use oseltamivir for 14 days after LAIV vaccination 1, 4

Duration of Protection

• Protection lasts only as long as oseltamivir dosing is continued 2
• Standard post-exposure prophylaxis duration is 10 days 1, 2
• During community outbreaks, prophylaxis can be extended up to 6 weeks in the general population 2