- Male or female subjects between the ages of 21 and 64 inclusive. For female subjects only: Female subjects will be included if they are post-menopausal or sterilized, or if they are of childbearing potential, they are not breastfeeding, their pregnancy test is negative, they have no intention of becoming pregnant during the course of the study, and are using adequate contraceptive drugs or devices. Medically acceptable methods of contraception that may be used by the subject and/or her partner are: oral contraceptives, progestin injection or implants, condom with spermicide, diaphragm with spermicide, IUD, vaginal spermicidal suppository, surgical sterilization or abstinence. Females using oral contraception must have started using the medication at least 4 weeks prior to screening. Surgical sterilization must have occurred at least 6 weeks prior to screening.