Tamiflu (Oseltamivir) for 8-Month-Old Infants with Influenza
Oseltamivir (Tamiflu) is a suitable and recommended treatment option for an 8-month-old infant diagnosed with influenza, with a recommended dosage of 3 mg/kg per dose twice daily for 5 days. 1
Dosing Recommendations for Infants
- For term infants aged 0-8 months, the recommended dosage is 3 mg/kg per dose twice daily for 5 days 1
- For an 8-month-old infant, oseltamivir should be administered orally without regard to meals, although administration with meals may improve gastrointestinal tolerability 1
- The commercially manufactured liquid formulation has a concentration of 6 mg/mL, and an appropriate measuring device such as a 3-mL or 5-mL oral syringe should be used instead of the syringe supplied with the medication 1
Efficacy in Infants
- Infants younger than 1 year are at increased risk of hospitalization and complications from influenza, making antiviral treatment particularly important in this age group 1, 2
- The FDA has approved oseltamivir for treatment of children as young as 2 weeks of age 1, 3
- Given preliminary pharmacokinetic data and limited safety data, the American Academy of Pediatrics supports the use of oseltamivir to treat influenza in both term and preterm infants from birth because the benefits of therapy are likely to outweigh possible risks of treatment 1, 2
Timing of Treatment
- Treatment should be initiated as soon as possible after symptom onset, ideally within 48 hours, as earlier treatment provides better clinical outcomes 1, 2
- However, treatment should still be offered even if more than 48 hours have elapsed since symptom onset, particularly for infants who are at high risk of complications 1, 2
- Treatment should not be delayed while waiting for confirmatory influenza test results 2
Safety Considerations
- The most common adverse effect of oseltamivir in children is vomiting, occurring in approximately 5% of treated patients 1, 2
- Despite previous concerns about neuropsychiatric adverse effects, reviews of controlled clinical trial data and ongoing surveillance have failed to establish a link between oseltamivir and neurologic or psychiatric events 1
- A study of 35 infants less than one year of age treated with oseltamivir during the 2009 H1N1 pandemic found that none developed neurological, dermatological, or gastrointestinal side effects associated with treatment 4
Clinical Evidence
- In a meta-analysis of randomized controlled trials, oseltamivir treatment reduced the duration of illness in children with laboratory-confirmed influenza by 17.6 hours, and the risk of otitis media was 34% lower in treated children 1
- A recent observational study of 1,300 children with influenza found that oseltamivir significantly reduced the intensity of symptoms, number of days of hospitalization, and post-infection complications 5
Practical Administration
- Oseltamivir is available as Tamiflu in capsule form and as a powder for oral suspension that is reconstituted to provide a final concentration of 6 mg/mL 1
- For the 6 mg/mL suspension, dosing should be calculated based on the infant's weight (3 mg/kg per dose) 1
- If the commercially manufactured oral suspension is not available, a suspension can be compounded by retail pharmacies based on instructions contained in the package label 1
Special Considerations
- For preterm infants, dosing recommendations are lower than for term infants due to potentially immature renal function 1
- For extremely preterm infants (<28 weeks), consultation with a pediatric infectious disease physician is recommended 1
- Breastfeeding should be encouraged even if the mother or infant has influenza 1