 - Female subjects had to be post-menopausal, surgically sterilized or using a reliable non-hormonal method of contraception. Examples of reliable non-hormonal methods of contraception include tubal ligation, hysterectomy, intrauterine device, or a barrier method combined with a spermicide. Hormonal contraceptives were not allowed because the effect of BIA 2-093 on the metabolism of oral contraceptives was not yet known. 