Investigation Of The Effect Of Steady State Filibuvir On The Pharmacokinetics Of Oral Contraceptives (Levonorgestrel And Ethinyl Estradiol)

This is an open-label, fixed sequence study to investigate the effect of filibuvir (600 mg BID on the pharmacokinetics of oral contraceptives steroids. Sixteen subjects who have been on any combination of ethinyl estradiol and levonorgesterol oral contraceptives for at least one consecutive month prior to Period 1 will be enrolled into the study. The study will be conducted over two 28 day menstrual cycles and Day 1 of each period is defined as the first day of dosing OC in each cycle. During the first cycle (Period 1), the subjects will receive OC QD for 21 days and filibuvir BID on Days 22 through 28. During the second cycle (Period 2) the subjects will receive OC QD and filibuvir BID for 21 days. The dosing of filibuvir will start in Period 1 (Days 22 - 28).