7. Females of childbearing age who are sexually active, do not use acceptable birth control (double barrier method), or are not abstinent. Abstinence is defined as no sexual activity for at least 3 months before the start of the study and the intention to abstain from sexual activity during the study period). Double barrier methods allowed include: condoms or diaphragms combined with spermicide use, intrauterine devices (IUD), and oral, transdermal, injectable or implantable hormonal medications (Ortho-Evra, Norplant, Depo-Provera, and similar prescription products) for at least one month before entering the study and continuing its use throughout the study. Birth control pills alone are not acceptable forms of birth control for this study.