Oseltamivir Prophylaxis for Influenza in Household or Close Contact Settings

Prophylactic Regimen Based on Age and Weight

For children 1-12 years, the American Academy of Pediatrics recommends weight-based dosing: ≤15 kg, 30 mg once daily for 10 days; >15-23 kg, 45 mg once daily for 10 days; >23-40 kg, 60 mg once daily for 10 days; >40 kg, 75 mg once daily for 10 days 1
For children 3 months to <12 months, the American Academy of Pediatrics recommends 3 mg/kg once daily for 10 days 1
For children <3 months, oseltamivir is not recommended unless the situation is judged critical 1

Oseltamivir has demonstrated 82-89% protective efficacy in preventing laboratory-confirmed influenza illness in household contacts, according to the Centers for Disease Control and Prevention 2, 3
The American Academy of Pediatrics states that chemoprophylaxis is not a substitute for vaccination, which remains the primary means of influenza prevention 2, 3, 4

The American Academy of Pediatrics recommends initiating prophylaxis for household or close family contacts of a confirmed influenza patient, due to potential exposure to both the index case and common environmental sources 5, 6
For high-risk individuals who have not yet been vaccinated or are within 2 weeks of vaccination, the Centers for Disease Control and Prevention recommends oseltamivir prophylaxis 1, 4

The American Academy of Pediatrics recommends standard post-exposure prophylaxis for 10 days after last known exposure 1, 5, 6
For community outbreaks, the Centers for Disease Control and Prevention recommends prophylaxis for up to 6 weeks during periods of influenza activity 3, 4

The Centers for Disease Control and Prevention states that oseltamivir prophylaxis does not interfere with antibody response to influenza vaccine 3, 7
For unvaccinated persons who have frequent contact with high-risk individuals during community outbreaks, the Centers for Disease Control and Prevention recommends considering oseltamivir prophylaxis 3, 8

For pregnant women and immunocompromised patients, the benefits of prophylaxis typically outweigh the risks when there is significant exposure, according to the Infectious Diseases Society of America 5
Children receiving influenza vaccine for the first time may require 6 weeks of prophylaxis, according to the Centers for Disease Control and Prevention 2, 3, 8

The American Academy of Pediatrics recommends that children <5 years (especially <2 years) and adults ≥65 years should be considered for prophylaxis when unvaccinated or exposed 9, 10
Residents of nursing homes and chronic care facilities should receive prophylaxis due to increased risk of influenza complications 9, 11
Patients with chronic pulmonary disease (including asthma, COPD, cystic fibrosis) should be considered for prophylaxis 9, 11
Patients with hemodynamically significant cardiovascular disease should receive prophylaxis 9, 10
Patients with chronic metabolic diseases (including diabetes mellitus), renal dysfunction, or hepatic disease should be considered for prophylaxis 9, 11
Immunocompromised patients, including those with HIV infection, malignancy, chemotherapy recipients, transplant patients, or those on chronic steroids, should receive prophylaxis 9, 11
Pregnant and postpartum women should be considered for prophylaxis 9, 10
Children and adolescents <19 years on long-term aspirin therapy should receive prophylaxis due to risk of Reye syndrome 9, 10
Patients with neurologic/neurodevelopmental conditions, such as cerebral palsy, epilepsy, stroke, muscular dystrophy, or spinal cord injury, should be considered for prophylaxis 9, 10
Patients with conditions compromising respiratory function, such as tracheostomy or mechanical ventilation, should receive prophylaxis 9, 10
Patients with extreme obesity (BMI ≥40 for adults) should be considered for prophylaxis 9, 10

Healthcare workers and institutional staff who are unvaccinated and have frequent contact with high-risk patients should be considered for prophylaxis during community outbreaks, as recommended by the Centers for Disease Control and Prevention 12