Reversible pituitary ovarian suppression induced by an LHRH agonist in the treatment of endometriosis--comparison of two dose regimens.

Buserelin [D-Ser(TBU)6-des Gly NH2(10) LHRH ethylamide], an LHRH agonist, was administered intranasally at two dose levels, 200 micrograms t.d.s or 300 micrograms t.d.s., to 20 women with proven endometriosis, many with recurrent disease. Both dose schedules achieved significant suppression of circulating 17 beta-oestradiol levels often to within the postmenopausal range, the larger dose inducing significantly greater suppression (P less than 0.05). Serum FSH values were suppressed below baseline but serum LH remained at pretreatment levels or above, whilst on treatment. Complete resolution of endometriotic deposits was achieved in 68% of cases following 6 months treatment with dramatic and long-standing relief of symptoms with no apparent dose difference. In all other subjects there was significant reduction in the extent of endometriotic deposits and improvement in American Fertility Society classification of disease stage. The most commonly occurring side effect was hot flushes; their intensity and frequency related to the degree of suppression of serum oestradiol and the dose of Buserelin administered.