 - Sexually active women of childbearing potential must agree to use adequate contraceptive measures, while on study and for 30 days after the last dose of study drug. All fertile female subjects and their partners must agree to use a highly effective method of contraception. Effective birth control includes a intrauterine device IUD plus one barrier method; or b 2 barrier methods. Effective barrier methods are male or female condoms, diaphragms, and spermicides creams or gels that contain a chemical to kill sperm. Note: Oral, implantable, or injectable contraceptives may be affected by cytochrome P450 interactions, and are not considered effective for this study. 