Three-stage combination oral contraceptives - contg. oestrogen with increasing doses of gestagen

摘要

Three-stage combination contraceptives contains (a) in the 1st stage, a low dose of oestrogen and a low dose of gestagen; (b) in the 2nd stage, a slightly increased (=2 fold) dose of oestrogen and a slightly increased (=1 1/2-fold) dose of gestagen; and (c) in the 3rd stage, an oestrogen dose no higher than in (b) and no lower than that in (a) and a further increased (=3 times the dose in (a)) dose of gestagen. The products give better compatibility and/or cycle control than 2-stage contraceptives; the components used in (a), (b) and (c) can be made different to overcome side-effects; e.g. a (19-nor) testosterone gestagen (with androgenic side-effects) can be used in (a) and (b) and a progesterone gestagen (with antiandrogenic activity) can be used in (c), and/or a 17 alpha-ethynyloestradiol oestrogen (with low gastric compatibility and metabolic side-effects) can be used in (a) and (b) and a natural oestrogen (without these side effects) can be used in (c). The oestrogen is pref. 17 alpha-ethynyloestradiol (I) and the gestagen is pref. norethisterone acetate (II), cyproterone acetate or D-norgestrel. The contraceptives are pref. formulated as tables (contg. carriers, flavour correctors and/or fillers) with 6-8 (esp. 7) tables corresp. to each stage.