- Female subjects of childbearing potential must have a normal menstrual cycle and a negative urine pregnancy test result prior to study entry. Women must be either post-menopausal or surgically sterile (hysterectomy, bilateral tubal ligation, or bilateral oopherectomy), or women of childbearing potential must use an effective method of birth control. Acceptable methods of birth control include hormonal contraceptives (i.e. pill, patch, ring, injection, implant), intrauterine device (IUD), diaphragm with spermicide or condom with spermicide.