Pharmacokinetics of Oseltamivir in Newborns and Infants

Treatment dose was oseltamivir 3 mg/kg/dose by mouth (PO) twice daily. Prophylactic dose was oseltamivir 1 mg/kg/dose PO once daily to infants \< 28 weeks postmenstrual age (PMA), 1 mg/kg/dose PO twice daily to infants 28 - 38 weeks PMA, and 3 mg/kg/dose PO once daily to infants \> 38 weeks PMA. Dosing in infants \< 28 weeks PMA was chosen based on unpublished data from Acosta et al. This data was obtained from phone contact with Dr. Peter Gal, co-author of the study. Dosing in infants 28 - 38 weeks PMA was chosen based on published data from Acosta et al.1 Dosing in infants \> 38 weeks PMA and less than 3 months postnatal age was chosen based on data from Kimberlin et al. Dosing in infants \> 38 weeks PMA and greater than 3 months postnatal age was per the recommendations of the Advisory Committee on Immunization Practices of the United States Department of Health and Human Services.