- Women of childbearing potential, or men of fathering potential, must be using adequate (in the investigator's opinion) birth control measures (e.g. abstinence, oral contraceptives, intrauterine device, barrier method with spermicide, or surgical sterilisation) during the study. Female subjects of childbearing potential must test negative for pregnancy prior to enrolling in the study. Post menopausal (cessation of menses for more than 2 years) women are eligible for this study.