- Subjects of childbearing potential must have a negative urine pregnancy test result and must not be lactating at Visit 1 and be willing and able to use an acceptable method of birth control (e.g., barrier methods used with a spermicidal agent, hormonal methods, IUD, surgical sterilization, abstinence) during the study. Women will not be considered of childbearing potential if one of the following conditions is documented on the medical history: a) Postmenopausal for at least 12 months prior to study; b) Without a uterus and/or both ovaries; or c) A bilateral tubal ligation at least six months prior to study enrollment.