Pharmacokinetics of oseltamivir according to trimester of pregnancy

Laura G. Greer, Richard D. Leff, Vanessa Laibl Rogers, Scott W. Roberts, George H. McCracken, George D. Wendel, Jeanne Sheffield

Research output: Contribution to journalArticle


The purpose of this study was to determine pharmacokinetic parameters for oseltamivir in all trimesters of pregnancy. Thirty pregnant women, 10 per trimester, who were receiving oseltamivir phosphate (75 mg) were recruited to study first-dose pharmacokinetics. Plasma samples were obtained at 0, 0.5, 1, 2, 4, 8, and 12 hours after the first dose. Samples were analyzed for oseltamivir and oseltamivir carboxylate levels. With the use of a noncompartmental model, we estimated the area-under-the-curve, maximum concentration, time-to-maximum concentration, and half-life. There were no significant differences in the pharmacokinetics of oseltamivir by trimester, except for an increased half-life in the first trimester for oseltamivir phosphate and an increased maximum concentration in the third trimester for oseltamivir carboxylate. The levels of oseltamivir carboxylate that were observed were within the range that was needed to achieve inhibitory concentrations at 50% for pandemic H1N1. The pharmacokinetics of oseltamivir does not change significantly according to trimester of pregnancy.

Original languageEnglish (US)
JournalAmerican Journal of Obstetrics and Gynecology
Issue number6 SUPPL.
StatePublished - Jun 2011
Externally publishedYes



  • influenza
  • oseltamivir
  • pharmacokinetics
  • pregnancy

ASJC Scopus subject areas

  • Obstetrics and Gynecology

Cite this

Greer, L. G., Leff, R. D., Rogers, V. L., Roberts, S. W., McCracken, G. H., Wendel, G. D., & Sheffield, J. (2011). Pharmacokinetics of oseltamivir according to trimester of pregnancy. American Journal of Obstetrics and Gynecology, 204(6 SUPPL.).