 2. Women who are pregnant, lactating, or of childbearing potential who are not using adequate contraceptive measures. The following are considered to be adequate methods of birth control: 1. intrauterine device IUD; 2. barrier protection; 3. a contraceptive implantation system Norplant; 4. oral contraceptive pills; 5. a surgically sterile patient; and 6. abstinence. All female subjects will have a negative pregnancy test prior to randomization. 