Pharmacokinetics of Raltegravir During Third Trimester Pregnancy and Post-Partum

This study will evaluate the pharmacokinetic disposition of raltegravir in pregnant HIV-1 infected women. These results will be compared to pharmacokinetic data obtained following pregnancy as well as to studies previously carried out in nonpregnant women and male patients. By determining the disposition characteristics for this specific patient population, antiretroviral (ARV) dosing can be optimized during pregnancy. Appropriate dosing is necessary to minimize adverse effects, slow progression of disease, and further reduce the risk for vertical transmission. Data will also be obtained on genital tract penetration and placenta transfer of raltegravir to the newborn.

The subjects enrolled in this study will take an antiretroviral based regimen containing raltegravir twice daily both during and after their pregnancy. The specific regimen will be chosen by their own primary care provider based on their antiretroviral history and resistance testing. They will undergo a series of blood sampling for pharmacokinetic analysis over 12 hours on two occasions; a) during their 3rd trimester and b) approximately 3 months postpartum. Concentrations of raltegravir in the infant will be assessed by cord and infant blood sample at delivery and a blood sample at approximately 3 months of age.

Hypothesis: The pharmacokinetic exposure of raltegravir as measured by the 12 hour area under the plasma concentration versus time curve (AUC0-12h) during third trimester pregnancy is similar to the AUC0-12h estimated three months post-partum.