Can Tamiflu Be Given to Family Members of Flu Patients?
Yes, oseltamivir (Tamiflu) should be given to family members of influenza patients as post-exposure prophylaxis, particularly for those at high risk of complications, and it demonstrates 68-89% protective efficacy when started within 48 hours of the index case's symptom onset. 1, 2
When to Initiate Prophylaxis
Household contacts should receive oseltamivir prophylaxis when:
- The index case (infected family member) has confirmed or suspected influenza and prophylaxis can be started within 48 hours of the index case's symptom onset 1, 2
- The contact is at high risk for influenza complications (children <2 years, pregnant women, immunocompromised individuals, elderly, those with chronic medical conditions) 3
- The contact is unvaccinated or was vaccinated less than 2 weeks prior (insufficient time for antibody development) 3, 1
- Otherwise healthy children who have close contact with infants <6 months or other high-risk children should also be considered for prophylaxis 3
Dosing Regimen for Post-Exposure Prophylaxis
Standard 10-day course after household exposure: 1
- Adults and children >40 kg: 75 mg once daily for 10 days 1
- Children 1-12 years (weight-based):
- Infants 3 months to <12 months: 3 mg/kg once daily for 10 days 1
- Infants <3 months: Not recommended unless situation is critical 1
Evidence for Effectiveness
The protective efficacy is substantial when used appropriately:
- Post-exposure prophylaxis provides 89% protective efficacy for individuals and 84% for households when started within 48 hours of index case symptom onset 2
- In a randomized controlled trial of 955 household contacts, oseltamivir reduced laboratory-confirmed influenza from 12% in placebo recipients to 1% in oseltamivir recipients 4, 2
- Among pediatric household contacts (1-12 years), prophylaxis reduced influenza incidence from 17% to 3% 4
- A separate study demonstrated 68% protective efficacy for individual contacts when combined with treatment of the index case 5
Important Clinical Considerations
Key points to optimize prophylaxis success:
- Prophylaxis does not interfere with antibody response to influenza vaccine, so unvaccinated contacts should still receive vaccination 1
- The index case does not need to receive oseltamivir treatment for prophylaxis to be effective in contacts, though treating the index case may provide additional benefit 2, 5
- Oseltamivir prophylaxis is not a substitute for vaccination, which remains the primary prevention strategy 3, 1
- During community outbreaks, prophylaxis can be extended up to 6 weeks for high-risk individuals or those with frequent contact with high-risk persons 1
Common Pitfalls to Avoid
- Do not delay prophylaxis waiting for laboratory confirmation of influenza in the index case during influenza season—clinical suspicion is sufficient to initiate prophylaxis 3
- Do not withhold prophylaxis from vaccinated high-risk individuals—vaccination provides incomplete protection and prophylaxis offers additional benefit (91% effective even in vaccinated elderly) 6
- Do not assume prophylaxis is unnecessary for healthy contacts—consider prophylaxis for healthy family members who have close contact with high-risk individuals, especially infants <6 months who cannot be vaccinated 3
- Remember the 48-hour window—prophylaxis is optimally effective when started within 48 hours of exposure to the index case 1, 2
Special Populations
- Pregnant women and immunocompromised patients: Benefits of prophylaxis typically outweigh risks with significant exposure 1
- Children receiving first-time influenza vaccination: May require up to 6 weeks of prophylaxis (until 2 weeks after the second vaccine dose) 3, 1
- Unvaccinated healthcare workers or caregivers: Should receive prophylaxis if they have frequent contact with high-risk individuals during community outbreaks 3