- Women must be postmenopausal for at least 2 years, surgically sterile, abstinent, or agree to practice an effective method of birth control if they are sexually active before entry and throughout the study. Effective methods of birth control include: prescription hormonal contraceptives, intrauterine device, double-barrier method, and male partner sterilization. Women of childbearing potential must have a negative urine pregnancy test at baseline, before receiving a dose of study drug