- All females must have a negative serum beta human chorionic gonadotropin test result at screening and a negative urine pregnancy test result at baseline. Female subjects must be either post-menopausal, surgically sterile or using an acceptable method of contraception. Acceptable surgical sterilization techniques are hysterectomy, bilateral tubal ligation with surgery at least 6 months prior to dosing and bilateral oophorectomy with surgery at least 2 months prior to dosing. Acceptable methods of contraception are an intrauterine device, contraceptive implant, oral contraceptive (stable dose of the same hormonal contraceptive product for at least 12 weeks prior to dosing), a vasectomized partner and a double-barrier method (condom + spermicide / diaphragm + spermicide).