- Female of child-bearing potential who is engaged in active heterosexual relations and is not using appropriate birth control methods. Appropriate methods of birth control will include: surgical sterilization at least 6 months prior to using study drug or sexual activity restricted to a vasectomized partner, barrier contraception with a condom or diaphragm in conjunction with spermicidal gel in use at least 30 days prior to using study drug OR sexual abstinence as a lifestyle.