- Women who are pregnant or woman of childbearing potential unwilling to practice acceptable contraception for the duration of the study (21 days). Females who are pregnant or nursing (breastfeeding) mothers or females of childbearing age who do not plan to use acceptable birth control measures, for the duration of the study. Adequate contraception is defined as hormonal (oral, injection, transdermal patch, implant, cervical ring), barrier (condom or diaphragm), intrauterine device (IUD) or monogamous relationship with vasectomized partner who has been vasectomized for 6 months or more prior to the subject's study entry.