 6. Must have a negative urine pregnancy test at the Screening Visit and use an adequate contraceptive method throughout the study if a woman of child-bearing potential. Women who are surgically sterile hysterectomy or tubal ligation or whose last menstruation was 12 months or more prior to the Screening Visit are considered to be of non-child-bearing potential. Acceptable forms of contraception include oral, implanted, or injected contraceptives intrauterine devices in place for at least 3 months estrogen patch and adequate barrier methods in conjunction with spermicide. Abstinence is considered an acceptable contraceptive regimen. 