- Women must be surgically sterile, 2 years postmenopausal, or, if of childbearing potential, using a medically accepted method of birth control (i.e., barrier method with spermicide, steroidal contraceptive [oral, transdermal, implanted, and injected contraceptives must be used in conjunction with the barrier method], or intrauterine device [IUD]) and agree to continued use of this method for the duration of the study.