Female subjects not willing to use proposed contraceptive methods. Use of prescription or non-prescription drugs [in particular known inhibitors of cytochrome 2C8 (Gemfibrozil, trimethoprim, glitazone, monteleucast, quercetin) or inducer (rifampin)], vitamins, herbal and dietary supplements (including St. John's Wort) within 14 days or 5 half-lives (whichever is longer) prior to the first dose of study medication. Excluded from this list are acetaminophen and paracetamol at doses of less than or equal to 2 grams/day, thyroid replacement therapy, and hormonal methods of contraception (including oral contraceptives, injectable progesterone, progestin subdermal implants and progesterone-releasing IUDs, but NOT postcoital contraceptive methods) and hormone replacement therapy which will be permitted throughout the study.