- Female subjects must be post menopausal for at least one year, surgically incapable of childbearing (hysterectomy or tubal ligation), or practicing an acceptable method of birth control (e.g., hormonal contraceptives, intrauterine devices, or barrier and spermicide). The subject should continue with the same method for the duration of the study. If a female subject is practicing an acceptable method of birth control, she must have maintained her normal menstrual pattern within the three months prior to study entry