 5. Use of effective method of contraception by females of childbearing potential and agreement to continue to practice an acceptable method of contraception for the duration of their participation in the study. Acceptable methods of contraception include oral, injectable, or implantable contraceptives; intrauterine devices, diaphragm plus spermicide; abstinence must agree to use double-barrier method if they become sexually active, transdermal patch, or any double barrier method including a vasectomized sexual partner. Women who have had a hysterectomy or tubal ligation at least 6 months prior to Visit 1 or who have been post-menopausal 