- Men or women of childbearing potential, not willing to employ adequate contraception (condoms, diaphragm, birth control pills, injections, intrauterine device [IUD], surgical sterilization, subcutaneous implants, or abstinence, etc.); the efficacy of oral contraceptives may be decreased in patients who receive p450-inducing anticonvulsants; for these patients, use of a second mode of contraception is recommended; patients of childbearing potential must utilize effective contraception and avoid becoming pregnant or fathering a child for 6 months after completing study drug