Investigational Medical Product: Tamiflu® 75 mg hard capsules~Objective: The main purpose of this study is to assess the potential neonatal exposure to oseltamivir during lactation by examining oseltamivir concentrations in maternal blood, urine, and breast milk/colostrum.~Study design: Single-country, multicenter, observational pharmacokinetic study~Enrolment and follow-up: Lactating women (up to 20 subjects) who present with clinical symptoms indicative of influenza will be recruited (a maximum of 6 months period of recruitment) to receive immediate treatment with oseltamivir (Tamiflu® 75 mg hard capsules, provided free of charges for the study) at a standard dose of 75 mg twice daily. These subjects will have a 12 hour pharmacokinetic plasma, urine and breast milk study undertaken after the steady state in oseltamivir concentrations (both active and inactive metabolites will be measured) is reached in blood, i.e. after three days after treatment. Subjects do not need laboratory confirmation of influenza infection for inclusion in this study, although the results of any virological tests that seek to confirm influenza infection will be recorded. Maternal venous blood (2 samples, one pre-dose sample and one 2.5-hours-after-dose sample), urine samples (obtained from total urine output within 12 h), and breast milk/colostrum samples (8 samples within 12 h) are taken to determine oseltamivir phosphate (inactive metabolite) and oseltamivir carboxylate (active metabolite) levels.~Safety: Adverse events (AEs) and serious adverse events (SAEs) will be recorded. SAEs will be reported to the Ethics Committee and Regulatory authorities according to the reporting requirements in Hungary.~Number of patients: A total of 20 lactating patients will be enrolled.~Number of centres: Up to 3 investigational sites in Hungary will participate in the study. All sites will belong to an academic institution.~According to the approved protocol amendment 1 (dated: 31/Aug/2010) the time schedule is the following: The patient visits are planned as soon as possible during the pandemic season in Q3-Q4 2010 and Q1-Q2 2011. The study will run until enrollment is completed and all study procedures have been completed for the last subject in 2011.
The main purpose of this study is to assess the potential exposure of neonates to oseltamivir during lactation by examining oseltamivir concentrations in maternal blood, urine, and breast milk in breastfeeding women who are treated with oseltamivir, an anti-flu medication.