- Female subjects of childbearing potential must be using adequate contraception (female of childbearing potential is defined as one who has not been postmenopausal for at least one year, or has not been surgically sterilised, or has not had a hysterectomy at least three months prior to the start of this study [Visit 1]). Adequate contraceptives include hormonal intra-uterine devices, hormonal contraceptives (oral, depot, patch or injectable), and double barrier methods such as condoms or diaphragms with spermicidal gel or foam.