1. Women of childbearing potential who do not practice an acceptable method of birth control. Acceptable methods of birth control in this study are: surgical sterilization, intrauterine devices, partner's vasectomy, a double-protection method (condom or diaphragm with spermicide), hormonal contraceptive drug (i.e., oral contraceptive, contraceptive patch, long-acting injectable contraceptive) with a required second mode of contraception.