For how many days should Oseltamivir (Tamiflu) be given to family members?

From the Guidelines

Tamiflu (oseltamivir) should be given to family members as post-exposure prophylaxis for 7 days after the last known exposure to influenza. The dosing for adults and children over 40 kg is 75 mg once daily, while children receive weight-based dosing (30-45 mg daily depending on weight) 1. For maximum effectiveness, prophylactic treatment should begin within 48 hours of exposure to someone with influenza. This recommendation is based on Tamiflu's mechanism of action as a neuraminidase inhibitor, which prevents the release of viral particles from infected cells, thereby reducing viral spread. Prophylaxis is particularly important for household contacts at high risk for complications, including elderly individuals, young children, pregnant women, and those with chronic medical conditions. Side effects may include nausea, vomiting, and headache, which can be minimized by taking the medication with food. Remember that Tamiflu prophylaxis is not a substitute for annual influenza vaccination, which remains the primary preventive measure against seasonal flu.

Some key points to consider:

• The American Academy of Pediatrics (AAP) recommends oseltamivir as the preferred postexposure chemoprophylaxis for patients with influenza A and/or B 1.
• The Centers for Disease Control and Prevention (CDC) recommends routine chemoprophylaxis with oseltamivir or zanamivir for 7 days after last known exposure 1.
• Oseltamivir is available in capsule and oral suspension formulations, and the dose should be adjusted based on creatinine clearance in patients with renal insufficiency 1.
• The most common adverse effects of oseltamivir are nausea, vomiting, and headache, which can be minimized by taking the medication with food 1.

It's essential to note that the effectiveness of oseltamivir in preventing influenza illness has been demonstrated in several studies, including a meta-analysis of 5 new randomized controlled trials that included 1598 children with laboratory-confirmed influenza 2. The balance between benefits and harms should be considered when making decisions about the use of oseltamivir for either treatment or chemoprophylaxis of influenza.

From the FDA Drug Label

2.3 Recommended Dosage for Prophylaxis of Influenza Initiate post-exposure prophylaxis with oseltamivir phosphate for oral suspension within 48 hours following close contact with an infected individual. Adults and Adolescents (13 years of age and older) The recommended dosage of oseltamivir phosphate for oral suspension for prophylaxis of influenza in adults and adolescents 13 years and older is 75 mg orally once daily (12.5 mL of oral suspension once daily) for at least 10 days following close contact with an infected individual and up to 6 weeks during a community outbreak. Pediatric Patients (1 year to 12 years of age) Table 1 displays the recommended oral dosage of oseltamivir phosphate for oral suspension for prophylaxis of influenza in pediatric patients 1 year to 12 years of age based on body weight and provides information about prescribing the formulation for oral suspension Prophylaxis in pediatric patients is recommended for 10 days following close contact with an infected individual and up to 6 weeks during a community outbreak

The recommended duration of oseltamivir (Tamiflu) for post-exposure prophylaxis in family members is at least 10 days following close contact with an infected individual, and can be given for up to 6 weeks during a community outbreak 3.

• For adults and adolescents (13 years and older), the dosage is 75 mg once daily.
• For pediatric patients (1 year to 12 years of age), the dosage varies based on body weight, as shown in Table 1. Key points:
• Initiate prophylaxis within 48 hours of close contact with an infected individual.
• Duration of prophylaxis: at least 10 days, and up to 6 weeks during a community outbreak.

From the Research

Tamiflu Prophylaxis for Family Members

• The duration of Tamiflu prophylaxis for family members is not explicitly stated in the provided studies 4, 5, 6, 7, 8.
• However, according to the study published in Pediatrics 4, prophylaxis should be provided to unimmunized family members and healthcare professionals with close contact with high-risk unimmunized children or infants who are younger than 6 months.
• The study does not specify the exact duration of prophylaxis, but it mentions that prophylaxis should be provided during the 2 weeks after immunization for high-risk children who have not yet received immunization.

General Guidelines for Tamiflu Use

• Tamiflu (oseltamivir) is effective in reducing symptom burden in those with influenza A or B infection, and is preventative against developing infection after exposure 5.
• The clinical effectiveness of oseltamivir for children with influenza A and B has been investigated in several studies 6, 7, 8.
• These studies suggest that oseltamivir can decrease the median duration of influenza-related symptoms by approximately 1 day if initiated within 48 hours of the onset of symptoms of influenza 6.

Important Considerations

• The emergence of naturally occurring or post-treatment oseltamivir-resistant influenza may limit its future use as a monotherapeutic antiviral treatment agent 5.
• Further evaluation of the clinical effectiveness of oseltamivir for influenza-infected patients, including those infected with A(H1N1)pdm09, is needed 8.