- Women must not be pregnant or lactating; women of child-bearing potential (women are considered not of childbearing potential if they are at least two years postmenopausal and/or surgically sterile) must have used adequate contraception (abstinence; barrier methods such as IUD, diaphragm with spermicidal gel, condom, or others; and hormonal methods such as birth control pills or others) since her last menses prior to study entry; women of child-bearing potential and men must agree to use adequate contraception 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