 - Sexually active men or women of child-bearing potential who are unwilling to practice adequate contraception during the study adequate contraception measures include, stable use of oral contraceptives or other prescription pharmaceutical contraceptives for 2 or more menstrual cycles prior to screening; intrauterine device IUD; bilateral tubal ligation; vasectomy; condom plus contraceptive sponge, foam, or jelly, or diaphragm plus contraceptive sponge, foam, or jelly Contraception is not required for men with documented vasectomy. Post-menopausal women must be amenorrheic for at least 12 months in order not to be considered of child-bearing potential. Pregnancy testing and contraception are not required for women with documented hysterectomy or tubal ligation. 