- Women of child-bearing potential and men having intercourse with a woman of childbearing potential must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation; should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her study physician immediately; Note: women are considered to be of child-bearing potential if they are not surgically sterile or are under the age of 65 and have menstruated within the last two years