2. Female subjects who have reached puberty and are sexually active and are unwilling to use acceptable methods of effective birth control for the duration of the study and continuing for 5 weeks after receiving the dose of study drug. Acceptable methods of effective birth control include sexual abstinence (males and females); double barrier method (male condom with spermicide in combination with one female barrier method [diaphragm, cervical cap, or contraceptive sponge)]; or hormonal birth control; or intra-uterine device.