 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 partner; and 6. Abstinence. Women who are 2years post-menopausal or surgically-sterile are not considered of childbearing potential. All female subjects will have a negative pregnancy test prior to randomization. 